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VOL.  XXXII 

no.  4 


'kP 

PSYCHOLOGICAL  REVIEW  PUBLICATIONS 


WHOLE  NO.  146 

19^3 


Psychological  Monographs 

EDITED  BY 

JAM'ES  ROWLAND  ANGELL,  Yale  University 
HOWARD  C.  WARREN,  Princeton  University  ( Review ) 

JOHN  B.  WATSON,  New  York  (/.  of  Exp.  Psychol.) 

SHEPHERD  I.  FRANZ,  Govt.  Hosp.  for  Insane  ( Bulletin )  and 
MADISON  BENTLEY,  University  of  Illinois  (Index) 


STUDIES  FROM  THE  PSYCHOLOGICAL  LABORATORY 
OF  THE  UNIVERSITY  OF  CHICAGO 


Certain  Factors  in  the  Development 
of  a  New  Spatial  Co-ordination 


BY 

*  v 

MARGARET  WOOSTER  C 


PSYCHOLOGICAL  REVIEW  COMPANY 

PRINCETON,  N.J. 


Agents:  G.  E.  STECHERT  &  CO.,  London  (2  Star  Yard,  Carey  St.,  W.  C.) 

Paris  (16  rue  de  Cond6) 


ACKNOWLEDGMENTS 


To  the  subjects  who  so  cheerfully  and  patiently  went  through 
with  the  often  protracted  series  of  sittings,  I  am  deeply  grateful. 
Dean  James  R.  Angell  I  wish  to  thank  for  generous  interest  in 
this  investigation  and  for  inspiring  instruction.  To  Dr.  Harvey 
A.  Carr,  under  whose  direction  the  investigation  was  carried  out, 
I  am  grateful  for  minutely  painstaking  and  searching  criticism, 
and  especially  for  the  freedom  which  he  prescribed  for  me  in 
working  out  my  problem.  Those  who  have  done  research  work 
under  Dr.  Carr’s  direction  will  understand  the  statement  that  it 
has  been  one  of  the  greatest  privileges  in  my  experience  to  feel 
the  inspiration  of  such  a  scientific  attitude  as  his. 


CONTENTS 

PAGE 

I.  INTRODUCTION— STATEMENT  OF  PROBLEM  i 

II.  APPARATUS  AND  METHOD .  4 

III.  DESCRIPTION  OF  EXPERIMENTAL  SERIES 

AND  RESULTS .  12 

STANDARD  SERIES .  1 3 

1.  Effect  of  Knowledge  of  Experimental  Conditions 

a.  Experiments  with  knowledge 

b.  Experiments  without  knowledge 

2.  Effect  of  Position  of  Body,  Head,  and  Eyes 

a.  Experiments  with  undistorted  vision 

b.  Experiments  with  distorted  vision 

VISUAL  LOCALIZATION  OF  SOUNDING  OBJECTS .  47 

1.  First  Group,  Using  Electric  Buzzer 

2.  Second  Group,  Using  Electric  Bell 

a.  With  vibration  visible 

b.  With  vibration  invisible 

LOCALIZATION  WITH  TOUCH .  58 

1.  Passive,  as  Result  of  Chance  Success 

2.  Active,  as  Check  at  Each  Localization 

LOCALIZATION  WITH  VISUAL  PERCEPTION  OF  DISTORTION  63 
LOCALIZATION  WITH  TACTUAL-KINAESTHETIC  CLUES 
FROM  LEFT  ARM .  67 

IV.  RETENTION  OF  THE  NEW  CO-ORDINATION. .  73 

V.  SPECIFICITY  OF  READJUSTMENT .  75 

VI.  RELATION  OF  READJUSTMENT  TO  DEFINITE 
LOCALIZING  ACTIVITY .  89 

VII.  SUMMARY  AND  CONCLUSIONS . 91 


I 


INTRODUCTION 

The  purpose  of  this  investigation  was  to  determine  exper¬ 
imentally  the  relative  influence  of  various  sensory  modes  of  re¬ 
action,  as  sight,  touch,  and  hearing,  in  the  building  up  of  a  new 
space  habit.  This  particular  habit  was  developed  by  the  subjects 
in  the  process  of  learning  to  localize  correctly  objects  seen  through 
prismatic  glasses  which  distorted  the  visual  field. 

The  perception  of  space  is,  to  a  greater  or  less  extent,  the 
product  of  individual  experience.  The  adult  is  able  to  adjust  him¬ 
self  spatially  to  the  outer  world  only  by  virtue  of  the  possession 
of  a  system  of  complex  habits  of  reaction.  These  habits  have  been 
slowly  and  painfully  acquired,  most  of  them  in  infancy.  But 
the  process  of  acquisition  as  it  occurs  in  infancy  is  forgotten,  and 
later  changes  in  space  reactions  come  so  gradually  that  the  details 
of  the  adjustment  are  not  noticed.  The  adult  learns  to  find  a 
new  keyhole  in  the  dark  in  much  the  same  way  that  the  child 
learns  to  pick  up  his  rattle.  Hence  it  is  easy  to  overlook  the  fact 
that  every  move  we  make  depends  for  its  nicety  and  accuracy 
upon  the  unified  functioning  of  an  exceedingly  intricate  reaction 
system — a  system  in  the  building  up  of  which  countless  simple 
reactions  have  played  a  part. 

It  would  be  of  great  importance  for  psychological  theory  to 
determine  the  mechanisms  underlying  the  development  of  this 
complex  system  of  adjustments.  Does  the  development  take  place 
on  a  purely  sensory-motor  level,  or  is  it  influenced  by  ideational 
factors  ?  Is  actual  movement  in  space  essential,  or  could  a  passive 
subject  gain  effective  perception  of  a  spatial  situation?  Do  all 
normal  individuals  develop  spatial  habits  in  the  same  way,  or 
are  there  individual  differences  in  the  matter? 

The  chief  problem  discussed  in  the  theoretical  literature  on 
the  genesis  of  psychological  space  so  far  has  concerned  the 
relative  importance  of  various  sensory  factors.  Taste  and  smell 


i 


2 


MARGARET  WOOSTER 


and  the  organic  and  cutaneous  modes  of  activity  other  than  con¬ 
tact,  are  by  common  consent  held  to  be  of  negligible  importance 
in  this  connection,  in  spite  of  the  contention  of  James  that  all 
sensations  possess  original  spatial  quality.  The  status  of  hearing 
is  in  dispute.  In  general,  psychologists  are  inclined  to  assign  it 
little  if  any  importance  as  a  spatial  sense.  Contact,  however,  has 
been  considered  to  be  highly  important  as  a  factor  in  space  per¬ 
ception,  this  attitude  being  correlative  with  the  popular  notion 
that  touching  an  object  is  the  final  test  of  its  real  existence.  To 
others  vision  has  seemed  the  spatial  sense  preeminent.  Vision 
and  touch,  it  is  held  by  some,  are  the  only  senses  that  “possess 
real  spatial  character,”  and  other  senses,  such  as  kinaesthesis, 
become  important  in  space  experience  only  by  virtue  of  their 
connection  with  these. 

While  an  enormous  quantity  of  experimental  work  has  been 
produced  bearing  on  the  spatial  aspects  of  the  various  senses 
taken  in  isolation,  almost  nothing  has  been  done  by  way  of  in¬ 
vestigating  experimentally  the  relative  influence  of  the  various 
sensory  factors  as  they  cooperate  in  the  development  of  complex 
types  of  spatial  reaction.  Speculation  has  been  supplemented,  it 
is  true,  by  observations  on  the  behavior  of  young  children  and 
of  animals;  on  the  reported  experiences  of  congenitally  blind 
persons  restored  to  sight;  and  on  certain  cases  of  alleged  ab¬ 
normalities  in  the  space  reactions  of  adult  individuals.  But  not 
only  has  none  of  the  data  so  adduced  as  evidence  been  gathered 
and  presented  in  a  scientifically  systematic  way,  but  it  does  not 
seem  likely  that  in  such  fields  of  observation  enough  experimental 
control  can  ever  be  introduced  to  insure  validity  for  the  con¬ 
clusions  drawn. 

It  is  possible,  however,  to  demonstrate  conclusively,  by  ex¬ 
perimental  procedure,  certain  central  facts  about  the  manner  in 
which  spatial  coordinations  may  develop.  If  we  cannot  get  at 
the  actual  initial  processes  in  the  development  of  the  complex 
world  of  space  for  any  individual,  we  can  at  least  investigate 
experimentally  the  building  up  of  certain  spatial  coordinations, 
by  observing  what  happens  when  an  individual  readjusts  himself 
to  space  relations  that  have  been  artificially  disturbed.  The  ex- 


THE  DEVELOPMENT  OF  A  NEW  SPATIAL  CO-ORDINATION  3 

perience  of  people  who  have  gradually  become  used  to  a  new 
pair  of  glasses  which  alters  in  any  noticeable  way  the  field  of 
vision,  offers  an  illustration  of  the  fact  that  it  is  possible  though 
practical  experience  to  , readjust  one’s  ordinary  coordinations 
in  such  a  way  as  to  harmonize  again  disturbed  spatial  relations. 

Strangely  enough  it  was  not  until  comparatively  recent  years 
that  the  idea  of  investigating  the  development  of  spatial  organ¬ 
ization  by  producing  and  then  overcoming  an  artificial  disorgan¬ 
ization,  was  conceived  and  carried  out.  In  1897  Professor  George 
M.  Stratton  published  his  celebrated  paper  on  “Vision  without 
Inversion.”  The  immediate  purpose  of  the  experiments  reported 
in  that  article  was  to  prove  that  inversion  of  the  retinal  image 
is  not  a  necessary  condition  of  upright  vision.  They  furnished 
also,  however,  a  striking  demonstration  of  the  predominantly 
empirical  character  of  spatial  organization.  Incidentally  they 
threw  some  light  on  our  particular  problem  of  the  relative  efficacy 
of  various  concrete  factors  in  adjustment. 

Stratton,  it  will  be  recalled,  in  his  main  experiment  adopted 
the  plan  of  wearing  glasses  constructed  from  lenses  which  com¬ 
pletely  reversed  the  retinal  image,  and  hence  directions  in  the 
field  of  vision,  so  that  objects  formerly  appearing  to  the  right 
now  appeared  to  the  left,  and  objects  formerly  in  the  upper  part 
of  the  field  of  vision  now  looked  to  be  in  the  lower  part.  In  other 
words,  on  first  assuming  the  glasses  the  entire  visual  scene  ap¬ 
peared  to  be  upside  down.  Stratton  wore  these  glasses  continously 
for  eight  days,  except  during  hours  for  sleeping,  when  he  was 
carefully  blindfolded.  He  went  about  his  ordinary  activities  some¬ 
what  as  usual.  He  found  that  not  only  was  he  able  gradually  to 
make  effective  practical  adjustment  to  the  changed  visual  situa¬ 
tion,  but  that  at  the  same  time  the  new  arrangement  came  to  seem 
more  and  more  natural  to  him,  until  at  the  end  of  eight  days 
things  no  longer  appeared  to  be  upside  down.  A  new  visual  sys¬ 
tem  had  even  in  that  short  time  been  more  or  less  completely 
organized,  and  harmonized  with  sense  impressions  from  differ¬ 
ent  fields  to  such  an  extent  that  his  space  world  was  again  unitary. 

This  experiment  of  Stratton’s  demonstrated  first  that  the  in¬ 
version  of  the  retinal  image  is  not  a  necessary  condition  of  normal 


4 


MARGARET  WOOSTER 


vision,  the  fact  which  he  originally  set  out  to  prove.  It  showed, 
second,  that  it  is  possible  in  the  give  and  take  of  ordinary  ex¬ 
perience  to  build  up  an  entirely  new  spatial  organization  in  which 
various  sensory  factors  come  to  be  associated  together  in  new 
ways. 

In  addition  to  establishing  these  general  facts,  Stratton  made 
valuable  observations  on  the  role  played  by  various  factors  con¬ 
tributing  to  the  process  of  readjustment.  It  was  his  main  purpose, 
however,  to  establish  the  general  fact  that  harmonious  read¬ 
justment  can  occur,  rather  than  to  study  the  specific  factors  con¬ 
cerned  in  the  process.  He  made  no  effort,  therefore,  during  the 
course  of  the  experiment  systematically  to  investigate  the  form¬ 
ation  of  any  one  coordination,  but  merely  noted  down,  as  the  ex¬ 
periment  progressed,  those  observations  which  seemed  to  him 
pertinent.  These  observations  constitute  a  valuable  contribution 
to  the  factual  study  of  the  more  general  aspects  of  space  per¬ 
ception,  but  additional  data  of  a  specific  and  quantitative  nature 
are  needed  as  a  basis  for  more  detailed  conclusions.  In  fact  it 
would  take  the  combined  results  of  many  individuals  to  warrant 
the  drawing  of  such  general  conclusions. 

It  is  the  aim  of  the  present  work,  then,  to  contribute  something 
toward  the  experimental  investigation  of  those  factors  in  the 
development  of  space  perception  which  Stratton  treated  only  in¬ 
cidentally.  We  know  now,  through  his  experiment,  that  disturbed 
space  relations  can  be  effectively  reorganized  in  experience.  The 
next  step  is  to  determine  how  such  a  reorganization  is  effected' — 
what  factors  cooperate,  what  their  relative  influence  is,  and  what 
their  mode  of  functioning. 

II 

APPARATUS  AND  METHOD 

Stratton’s  method,  while  admirable  for  his  purpose,  is  far  too 
complex  for  ours,  and  would  involve  too  much  fatigue  and  in¬ 
convenience  to  be  employed  with  any  considerable  number  of 
subjects.  The  essential  nature  of  the  process  in  question  would  be 
the  same  were  the  observers  to  be  subject  to  the  disturbed  con- 


THE  DEVELOPMENT  OF  A  NEW  SPATIAL  CO-ORDINATION  5 

ditions  for  only  a  short  time  each  day,  instead  of  continuously. 
If  under  such  circumstances  reorganization  could  be  secured  at 
all,  it  would  permit  of  definite  experimental  control  and  would 
yield  results  just  as  significant  for  the  general  theory  of  space 
perception  as  would  those  obtained  in  more  complex  situations, 
in  which  exact  control  would  be  almost  impossible. 

We  finally  determined  to  use,  instead  of  Stratton’s  180  degree 
reversing  lenses,  a  pair  of  prismatic  glasses  which  produced  an 
angular  deviation  of  the  visual  field  of  about  21  degrees.  These 
the  subjects  wore  for  20  minutes  each  day,  while  working  at  the 
simple  task  of  localizing,  by  reaching  movements,  objects  ar¬ 
ranged  in  definite  positions.  We  found  that  under  these  circum¬ 
stances  there  was  a  gradual  and  progressive  tendency,  more 
or  less  completely  fulfilled  according  to  experimental  conditions, 
to  overcome  the  wide  initial  visual  distortion  and  to  localize  the 
objects  more  and  more  accurately.  We  then  planned  a  series 
of  experiments  with  the  object  of  determining  first,  what  are 
the  sensory  or  other  factors  concerned  in  this  particular  process 
of  readjustment;  and  second,  what  is  the  relative  efficacy  of 
the  different  factors  involved. 

The  glasses  used  in  our  experiment  consist  of  two  40  degree 
optical  prisms  producing  an  angular  deviation  of  about  21  de¬ 
grees.  These  were  mounted  in  a  light  aluminum  frame  in  such  a 
way  that  they  can  be  easily  adjusted  back  and  forth;  or  turned 
in  any  one  of  the  four  directions — right,  left,  up,  or  down.  The 
prism  used  for  the  left  eye  consists  of  two  20  degree  prisms  com¬ 
bined,  and  produces  a  deviation  slightly  greater  than  the  prism 
for  the  right  eye,  but  not  great  enough  to  cause  any  trouble  in 
combining  the  images  for  the  two  eyes.  Throughout  the  experi¬ 
ments  we  were  thus  able  to  work  with  binocular  vision,  in  which 
respect  our  conditions  are  superior  to  those  of  Stratton,  who 
relied  on  monocular  vision. 

Careful  measures  were  taken  to  insure  that  no  light  should 
enter  the  eyes  of  our  subjects  except  that  which  came  through  the 
prisms.  The  light  frame  in  which  the  prisms  are  mounted,  is  so 
shaped  as  to  fit  closely  over  the  nose.  To  the  upper  and  lower 


6 


MARGARET  WOOSTER 


sides  are  glued  fitted  pieces  of  black  cloth-covered  felt  about  a 
fourth  of  an  inch  thick,  so  shaped  as  to  extend  back  and  rest 
against  the  forehead  and  cheeks.  To  the  ends  of  the  frame  are 
attached  double  flaps  of  black  cloth  which  extend  back  toward 
the  ears.  The  glasses  were  kept  in  place  by  an  adjustable  rubber 
band  extending  from  the  ends  of  the  frame  around  the  back  of 
the  subject’s  head.  When  they  were  put  on,  a  piece  of  cotton  was 
slipped  under  the  lower  part  of  the  frame,  over  the  cheeks  and 
nose,  in  such  a  way  as  to  fill  up  any  space  that  might  remain. 
Thus  only  light  that  came  through  the  prisms  was  admitted  to 
the  eve. 

j 

At  first  subjects  usually  felt  somewhat  disturbed,  on  account 
of  the  strangeness  of  the  prismatic  effect,  and  the  unusual  limita¬ 
tion  of  the  visual  field  by  the  frame  of  the  glasses.  But  this  feel¬ 
ing  soon  wore  off,  and  after  two  or  three  sittings  they  reported 
feeling  quite  natural  and  at  ease.  The  glasses  are  fairly  light  and 
not  uncomfortable.  It  is  easy  to  obtain  a  relatively  clear  single 
image  of  any  object  by  turning  the  head  in  the  proper  direction. 

While  wearing  these  glasses  the  subject  was  set  to  work  at  a 
task  offering  favorable  conditions  for  the  formation  of  a  new 
spatial  coordination.  He  was  seated  at  a  table  facing  a  row  of 
objects  which  he  was  to  localize  by  reaching  out  with  his  right 
arm  and  right  index  finger.  (See  Plate  I.)  These  objects,  small 
electric  buzzers  (C),  are  suspended  at  about  the  level  of  the 
subject’s  eyes  from  a  horizontal  iron  rod  (R)  elevated  35  cm. 
above  the  top  of  the  table.  The  rod  is  held  in  place  by  three 
wooden  uprights  fastened  to  a  board  at  the  back  of  the  table 
which  joins  two  other  boards  at  the  ends  (G,  G)  to  form  a  box¬ 
like  upper  extension  of  the  table,  open  in  front. 

Now  with  the  prisms  adjusted  to  cause  a  deviation  to  the  right, 
a  buzzer  which  was  really  directly  in  front  of  the  subject  ap¬ 
peared  to  be  about  25  cm.  to  his  right,  and  in  pointing  it  out  he 
touched  a  point  25  cm.  farther  to  the  right  than  the  buzzer  actual¬ 
ly  was,  there  being  no  incentive  to  correct  to  the  left.  In  order  that 
the  subject  might  not  see  his  arm  when  reaching  for  the  buzzers, 
and  thus  be  tempted  to  correct  the  obvious  error,  a  wooden 
cover  was  provided  for  the  box-like  extension,  attached  at  the 


THE  DEVELOPMENT  OF  A  NEW  SPATIAL  CO-ORDINATION  7 


ends  to  the  top  of  the  end  boards  (G,  G).  The  subject,  seated  in 
the  chair  with  base  at  I,  thus  looked  over  the  cover  at  the  objects 
(C)  but  localized  them  by  reaching  out  his  arm  under  the 
cover.  When  leaning  back  in  the  chair  between  trials,  the  sub¬ 
ject  was  prevented  from  seeing  his  body  by  the  frame  of  the 
glasses.  Hence  at  no  time  while  wearing  the  glasses  was  any  part 
of  the  subject’s  body  visible  to  him. 

In  certain  of  the  series  it  was  necessary  that  the  position  of 
the  subject’s  finger  be  observable  by  the  experimenter,  seated 
back  of  the  apparatus,  while  not  by  the  subject  himself.  There¬ 
fore  just  beneath  the  buzzers  there  is  a  narrow  slit,  between  the 
cover  and  the  back  of  the  extension,  through  which  the  ex¬ 
perimenter  could  look  down  and  note  the  position  of  the  sub- 


8 


MARGARET  WOOSTER 


ject’s  finger.  It  was  necessary  also  that  this  slit  be  widened  at 
times  in  order  that  the  subject  might  at  the  end  of  his  reaching 
movement  see  his  finger  and  thus  note  his  error;  or  in  order  that 
the  buzzer  might  be  lowered  down  through  the  slit  in  such  a 
position  that  the  upper  half  would  be  visible  to  the  subject,  and 
the  lower  half,  although  beneath  the  cover  and  invisible,  could 
be  touched  by  the  subject  as  he  reached  out.  To  provide  for  the 
three  different  widths  of  the  slit  thus  necessary,  the  back  part  of 
the  cover  is  made  adjustable,  or  capable  of  being  moved  from 
back  to  front  and  vice  versa,  to  widen  or  narrow  the  slit.  It  is 
desirable  that  this  movable  part  of  the  cover  have  a  thin  edge  and 
a  smooth  under  surface  furnishing  no  tactual  clues  of  position, 
and  so  it  is  made  of  a  strip  of  glass  about  18  cm.  wide,  with  the 
upper  surface  painted  black.  This  strip  (B)  is  set  in  a  sliding 
wooden  frame  which  can  be  pushed  part  way  back  under  the  front 
or  wooden  part  of  the  cover  (A).  The  distances  by  which  this 
adjustable  strip  in  its  frame  shall  be  moved  to  front  or  back 
is  regulated  by  means  of  brass  stops  at  the  ends  of  the  frame. 
In  this  way  the  strip  can  easily  be  set  for  any  one  of  the  three 
different  widths  of  the  slit  desired. 

The  position  of  the  buzzers  along  the  rod  and  their  height 
above  the  table  can  be  easily  changed.  The  detail  diagram  (Plate 
II)  shows  how  this  can  be  done.  Each  buzzer  is  clamped  to  the 
lower  end  of  a  long  screw.  To  this  screw  is  attached  a  brass  clamp 
through  which  the  buzzer  can  be  adjusted  up  and  down.  The 
clamp  fits  over  the  iron  rod  and  can  be  securely  attached  to  it 
at  any  position  by  means  of  a  small  thumbscrew  at  the  back. 
The  buzzer  can  thus  be  raised  (after  loosening  the  thumb  screw 
and  the  small  nut)  by  lifting  the  clamp  off  the  rod,  and  setting  it 
toward  the  bottom  of  the  screw.  It  can  be  lowered  by  setting  the 
clamp  toward  the  top  of  the  screw.  The  clamp  can  be  put  in  the 
same  position  on  the  rod,  or  in  another  position,  and  screwed  in 
place  as  before.  In  the  figure  one  buzzer  is  shown  raised  and  an¬ 
other  lowered  half  way  through  the  slit.  In  actual  practice  all  the 
buzzers  are  at  the  same  height  in  the  same  experiment. 

The  buzzers  are  connected  with  two  dry  cell  batteries  kept  in 
a  box  attached  to  the  back  of  the  apparatus.  They  are  operated 


THE  DEVELOPMENT  OF  A  NEW  SPATIAL  CO-ORDINATION  9 


Plate  II 


by  means  of  a  row  of  push  buttons  arranged  near  the  battery  box. 
The  light  flexible  wires  from  the  buzzers  hang  inconspicuously 
down  over  the  rod  at  the  back.  Also  at  the  back  of  the  table,  to 
the  experimenter’s  right,  is  a  shelf  for  her  use  in  recording  data, 
and  to  her  left  a  small  shelf  for  extra  buzzers.  None  of  these  parts 
of  the  apparatus  are  in  view  of  the  subject. 

In  most  of  the  experimental  series  it  was  necessary  that  the 
subject  should  not  be  able  to  perceive  the  extent  and  direction  of 
his  error  by  noting  the  position  of  the  experimenter’s  head  when 
she  bent  over  to  get  the  record.  To  prevent  this,  two  different 
methods  were  used.  At  first  the  subject  was  merely  asked  to  close 


10 


MARGARET  WOOSTER 


his  eyes  as  soon  as  the  localization  was  made.  This  proving  un¬ 
satisfactory,  a  black  curtain  (D,  Plate  I)  was  arranged  to  shut 
off  the  view  of  the  buzzers  after  each  localization.  It  operates  be¬ 
tween  two  vertical  iron  rods  (H,  H)  by  means  of  a  system  of 
rings,  screw  pulleys  (E,  E),  and  cords,  which  enable  the  experi¬ 
menter  to  manipulate  the  curtain  easily  and  quickly  by  the  use  of 
one  hand  behind  the  apparatus. 

The  chair  in  which  the  subject  was  seated  is  a  small  armless 
swivel  chair  of  adjustable  height,  easily  rotated.  It  was  kept 
in  the  same  position  throughout  the  sittings,  15  cm.  in  front  of  the 
line  connecting  the  front  legs  of  the  table,  the  center  of  it  12  cm. 
to  the  left  of  the  mid-point  of  that  line.  The  experimenter  sat 
on  a  high  office  stool  back  of  the  apparatus  and  just  opposite 
the  subject.  (Base  of  stool  shown  at  J.) 

A  few  minor  points  will  complete  the  description  of  the  ap¬ 
paratus.  The  iron  rod  is  covered  with  rubber  tubing  to  prevent 
jarring  and  modification  of  the  sound  of  the  buzzers.  Just  back 
of  the  board  which  forms  the  back  of  the  extension,  is  painted  a 
centimeter  scale  (reading  from  right  to  left  from  the  subject’s 
point  of  view)  on  which  the  position  of  the  subject’s  finger  at 
any  localization  can  be  read  off  by  the  experimenter.  A  vertical 
black  line  painted  on  the  front  face  of  each  buzzer  makes  it  more 
easily  localizable.  The  whole  apparatus  with  the  exception  of  the 
buzzers  is  painted  a  dull  black,  the  lines  of  the  scale  being  marked 
in  white. 

The  dimensions  of  the  chief  parts  of  the  apparatus  not  already 
given  are  as  follows:  top,  60.5  cm.  by  121  cm.;  height,  78  cm.; 
height  of  cover  above  table,  27.5  cm. ;  diameters  of  buzzers, 
4.5  cm. 

The  general  order  of  procedure  in  the  experiments  was  about 
as  follows.  On  the  first  day  the  subject  was  given  a  preliminary 
test  for  accuracy  of  normal  localization  of  the  buzzers  by  hand 
movement,  without  the  glasses.  On  the  second  day  he  wore  the 
glasses,  and  was  instructed  to  localize  the  buzzers  in  the  same  man¬ 
ner  as  at  the  first  sitting,  as  they  appeared  to  him,  disregarding  the 
fact  of  distortion.  Under  these  conditions  it  was  found  that  the 
subjects,  influenced  consciously  or  unconsciously  by  certain  sen- 


THE  DEVELOPMENT  OF  A  NEW  SPATIAL  CO-ORDINATION  u 


sory  or  other  factors,  showed  in  succeeding  sittings  a  tendency 
to  approach  closer  and  closer  to  the  actual  or  normal  standard 
of  localization.  For  instance  in  the  first  day’s  sitting  with  dis¬ 
torted  vision  subject  R.  reacted  on  the  average  18  cm.  to  the 
right  of  the  actual  position  of  a  buzzer;  in  the  second  day’s 
sitting  the  average  distance  from  the  true  position  was  only  16.5 
cm. ;  in  the  third,  only  14.5  cm.,  the  fourth  12  cm.,  and  so  on. 

The  original  aim  of  the  experiments  was  to  continue  the  sit¬ 
tings  for  each  subject  either  until  he  had  completely  ‘‘overcome 
the  effects  of  the  distortion”,  as  happened  in  many  cases;  or 
until  he  had  reached  the  limit  of  improvement.  Since  it  was  im¬ 
possible  for  many  of  the  subjects  to  continue  with  the  sittings 
until  such  a  limit  had  been  reached,  the  latter  requirement  had  to 
be  given  up.  But  all  the  subjects  whose  results  are  considered  in 
the  group  comparisons  either  “overcame  the  effects  of  the  dis¬ 
tortion”  in  less  than  10  sittings,  or  continued  until  10  sittings 
with  distorted  vision  had  been  taken. 

The  time  of  day  for  the  sittings  was  kept  constant  for  each 
subject  as  nearly  as  possible,  and  was  very  rarely  changed.  In 
general  each  subject  took  one  sitting  a  day,  six  days  a  week, 
although  occasionally  it  was  necessary  to  omit  two  days  out  of 
the  seven.  Each  sitting  lasted  exactly  20  minutes.  In  that  time 
20  localizations  were  made,  five  for  each  of  four  different  posi¬ 
tions  of  the  buzzers  along  the  scale,  the  interval  between  the 
“localizations”  or  trials  being  60  seconds  throughout  all  the  ex¬ 
periments.  Such  a  long  interval  was  made  necessary  by  the  cir¬ 
cumstance  that  in  certain  of  the  series  adjustments  of  the  ap¬ 
paratus  which  required  that  much  time  had  to  be  made  in  the 
interval. 

During  the  interval  conversation  between  the  subject  and  ex¬ 
perimenter  was  permitted  and  in  fact  encouraged,  first  that  the 
subject  might  feel  at  ease  and  natural,  and  second  that  he  might 
get  the  habit  of  making  his  localizations  in  an  unstudied  and 
automatic  manner  just  as  he  would  reach  out  for  an  object  under 
the  conditions  of  everyday  life.  The  effort  was  made  to  get  each 
subject  to  give  himself  up  freely  to  the  conditions  of  the  ex¬ 
periment.  The  directions  called  for  a  disregard  of  the  fact  of 


12 


MARGARET  WOOSTER 


distortion,  and  required  the  subject  to  react,  although  carefully, 
without  self-consciousness  or  critical  analysis  of  the  nature  of 
the  localizing  movement  or  of  the  possible  error.  Introspective 
comments  were  not  asked  for  until  after  the  final  sitting,  but  re¬ 
marks  made  spontaneously  were  carefully  noted  during  the  series ; 
and  if  a  peculiar  tendency  in  the  results  developed  at  any  time  a 
question  was  put  by  the  experimenter  relative  to  the  subject’s 
attitude  or  understanding  of  the  directions.  Unusual  bodily  con¬ 
ditions — of  extreme  fatigue,  excitement,  etc. — were  reported  and 
recorded  by  the  experimenter. 

In  all  72  subjects  were  used  in  the  main  experiments — five 
being  Instructors  in  the  Department  of  Psychology  of  the  Uni¬ 
versity  of  Chicago,  40  graduate  students  in  the  University  (most 
of  these  in  the  Department  of  Psychology)  and  27  upperclassmen 
taking  a  course  in  psychology.  The  writer  conducted  all  of  the 
experiments  in  person,  except  that  at  two  different  times  of  emer¬ 
gency  fellow  graduate  students,  Miss  Dorritt  Stumberg  and  Miss 
Katherine  Ludgate,  very  kindly  helped  out  by  each  giving  three 
or  four  sittings  to  two  subjects  already  started  in  a  series.  The 
writer  herself  acted  as  subject  in  all  the  experimental  series  pos¬ 
sible,  while  others  acting  as  experimenter,  and  with  conditions  as 
nearly  like  those  for  the  other  subjects  as  could  be  arranged.  In 
this  way  she  took  series  A-i,  B-i,  C-2,  and  D. 

The  experiments  here  discussed  extended  over  a  period  of 
about  12  months. 


Ill 

DESCRIPTION  OF  EXPERIMENTAL  SERIES  AND 

RESULTS 

There  has  been  much  disagreement  concerning  the  relative  ef¬ 
ficacy  of  the  various  modes  of  sensory  reaction  in  the  develop¬ 
ment  of  space  habits.  Particularly  has  this  been  the  case  with  re¬ 
spect  to  sight  and  touch  (including  kinaesthesis).  Whether  or 
not  hearing  is  a  “spatial  sense,”  or  may  contribute  anything  to 
the  development  of  an  organized  system  of  spatial  reactions,  is 
also  a  much  disputed  question.  Taste  and  smell  are  almost 


THE  DEVELOPMENT  OF  A  NEW  SPATIAL  CO-ORDINATION  13 

universally  held  to  be  of  negligible  significance  in  this  respect. 
Our  investigation,  therefore,  has  to  do  with  the  relative  efficacy 
of  hearing,  sight,  and  touch,  as  factors  contributing  to  the  form¬ 
ation  of  the  new  spatial  coordination  developing  under  the  con¬ 
ditions  of  our  experiment. 

There  were  five  main  series  of  experiments.  The  first  (A) 
was  given  as  a  standard  series  for  purposes  of  comparison  with 
later  series.  Records  were  secured  from  a  group  of  subjects 
showing  their  manner  of  localization  of  the  buzzers  from  day 
to  day,  with  distorted  vision,  but  without  the  sensory  clues 
the  influence  of  which  was  later  to  be  tested.  For  this  series 
the  slit  at  the  back  of  the  cover  was  so  narrowed  that  the  sub¬ 
ject  could  not  see  his  finger  after  reacting,  nor  touch  the  buzzer. 
The  buzzer  was  not  sounded  as  the  signal  for  reaction,  but  merely 
pointed  out  by  finger  movement. 

In  the  second  series  (B),  designed  to  test  the  efficacy  of  sound, 
conditions  were  exactly  as  in  the  first  except  that  the  buzzer  was 
sounding.  In  the  third  series  (C),  to  test  the  efficacy  of  touch, 
the  buzzer  was  lowered  half  way  down  through  the  slit  so  that 
when  a  correct  localization  occurred  there  would  be  contact  of 
the  finger  with  the  buzzer.  In  the  fourth  series  (D),  to  test  the 
efficacy  of  sight  of  the  localizing  finger,  the  slit  was  widened  so 
that  the  finger  tip  could  be  seen  after  the  localization  had  been 
made,  and  the  buzzer  was  raised  high  enough  to  prevent  contact. 
In  the  fifth  series  (E),  designed  to  test  the  influence  of  taetual- 
kinaesthetic  sensations  from  the  left  arm,  no  buzzers  were  used. 
The  subject  extended  his  left  arm  over  the  cover,  bending  the 
index  finger  down  through  the  slit,  and  localized  this  finger  as 
the  buzzer  was  localized  in  preceding  series,  by  a  reaching  move¬ 
ment  of  the  right  arm  under  the  cover. 

STANDARD  SERIES 

1.  Effect  of  Knowledge  of  Experimental  Conditions 

a.  Experiments  With  Knowledge 

For  the  standard  series,  four  buzzers  were  set  along  the  rod 
at  the  positions  53,  66,  79,  and  92  on  the  scale.  The  total  length 


14 


MARGARET  WOOSTER 


of  the  scale  being  20  cm.,  this  means  that  they  were  set  toward  the 
left  end,  in  such  a  position  that  they  were  directly  in  front  of 
the  subject.  Distorted,  they  appeared  shifted  about  25  cm.  farther 
to  his  right.  On  the  first  day  the  subject  was  given  10  trials  for 
normal  accuracy  of  localization  of  the  buzzers,  without  the 
glasses.  At  the  second  sitting  he  began  the  series  with  distorted 
vision.  The  experimenter  first  instructed  the  subject  as  to  the 
proper  position  of  the  chair,  and  then  placed  his  right  arm  in 
front  of  him  more  or  less  parallel  to  the  edge  of  the  table.  She 
told  him  that  at  the  signal  “Ready”  he  was  to  assume  this  posi¬ 
tion,  but  not  to  feel  that  the  position  was  to  be  rigidly  defined — 
that  the  only  object  was  to  get  a  uniformly  free  sweep  of  the 
arm.  The  subject  was  told  also  that  he  would  work  in  ignorance  of 
the  purpose  of  the  experiment,  and  was  cautioned  not  to  talk  to 
other  subjects  who  had  finished,  about  that  purpose.  Then  he  was 
given  the  following  instructions,  typewritten,  and  asked  to  study 
them  carefully: 

“When  I  point  out  one  of  these  four  buzzers  by  placing  my 
finger  on  it,  localize  it  as  in  preceding  series  without  the  glasses 
by  a  direct  movement  of  the  right  index  finger  to  the  point  just 
below  the  midpoint  of  the  buzzer  indicated.  The  glasses  will  give 
a  distorted  view  of  the  buzzers,  but  pay  no  attention  to  this  fact 
in  making  your  localizations,  simply  taking  pains  to  localize  the 
buzzer  as  accurately  as  possible  as  it  appears  to  you.  You  will 
have  no  means  of  judging  the  accuracy  of  your  localizations, 
so  pay  no  attention  to  the  possible  nature  of  errors,  but  reach 
out  directly  to  the  buzzer,  in  a  natural  and  automatic  manner, 
concentrating  your  attention  on  the  sight  of  the  buzzer.  In  making 
the  localizing  movement,  move  your  head  and  body  freely,  as  you 
choose. 

“When  you  have  touched  the  board,  close  your  eyes  and  keep 
your  finger  in  place  until  I  say  ‘All  right.’  Then  relax  in  your 
chair  and  open  your  eyes  if' you  wish.  When  I  say  ‘Ready’  assume 
your  former  position  with  your  arm  in  place  ready  to  react  as 
before.  There  will  be  one  trial  every  60  seconds,  and  the  stimuli 
will  be  given  in  irregular  order.  You  may  converse  on  indifferent 
topics  between  trials,  but  at  the  signal  “Ready”,  which  will  be 


THE  DEVELOPMENT  OF  A  NEW  SPATIAL  CO-ORDINATION  15 


given  two  seconds  before  the  stimulus,  all  conversation  will  cease.” 

After  the  subject  had  read  these  instructions  the  glasses  were 
put  on  him  by  the  experimenter  and  he  swung  around  in  the  chair, 
facing  the  buzzers.  The  point  is  to  be  emphasized  that  the  sub¬ 
ject,  in  making  his  localizations,  had  no  direct  sensory  means  of 
judging  their  accuracy.  The  buzzers  were  not  sounding.  The  slit 
was  so  narrowed  that  the  subject  could  not  see  his  finger  when 
he  had  made  a  localization.  In  order  that  he  might  not  gain 
knowledge  concerning  the  direction  and  extent  of  his  error 
through  noticing  the  position  of  the  experimenter’s  head  when 
she  bent  over  to  take  the  record,  the  instructions  are  explicit 
that  the  subject  shall  close  his  eyes  as  soon  as  he  has  touched  the 
board,  and  not  open  them  until  she  says  “All  right”  which  means 
that  the  position  of  the  finger  has  been  noted  and  that  the  ex¬ 
perimenter  has  assumed  her  usual  position  again.  Great  care  was 
taken  in  regard  to  this  point. 

While  the  subject  was  not  told  what  was  the  direction  of  the 
deviation,  in  most  cases  he  found  it  out  during  the  first  sitting, 
being  familiar  with  the  normal  appearance  of  the  apparatus  and 
knowing  how  the  prisms  were  set  in  the  glasses.  But  there  were 
no  clues  to  enable  him  to  realize  the  extent  of  his  error  from 
day  to  day.  The  fact  that  there  was  no  such  realization,  is  proved 
by  the  comments  of  the  subjects,  who  confessed  themselves  in 
the  dark  and  frequently  made  absurd  estimations  of  the  amount  of 
their  errors.  But  this  group  did  work,  it  must  be  noted,  with 
some  knowledge  of  the  experimental  conditions. 

The  results  of  this  first  series  with  distorted  vision  are  sur¬ 
prising.  They  indicate  that  there  is  from  the  first  localization,  a 
progressive  tendency  on  the  part  of  most  subjects  gradually  to 
approach  the  actual  position  of  the  buzzer.  In  general  the  rate 
of  readjustment  is  slow.  Of  the  initial  linear  deviation,  which 
in  this  group  averages  for  the  four  buzzers  21.1  cm.,  only  40.5 
per  cent  on  the  average  was  recovered  in  the  first  10  days.  How¬ 
ever  for  the  six  subjects  in  the  group  who  were  kept  at  the  task 
until  the  limit  of  improvement  was  apparently  reached  (until 
at  least  five  sittings  in  succession  showed  no  improvement)  the 
total  percentage  of  readjustment  amounted  to  59  per  cent  over 


i6 


MARGARET  WOOSTER 


the  initial  deviation.  This  means  that  in  spite  of  the  fact  that 
these  subjects  had  no  sensory  clues  as  to  the  actual  position  of 
the  buzzers,  they  still  “readjusted”  to  the  new  visual  situation, 
to  the  extent  that  they  learned  to  localize  the  buzzers  at  a  point 
about  60  per  cent  nearer  their  actual  position  than  they  had  local¬ 
ized  them  at  the  beginning  of  the  series.  In  other  words  we  have 
an  ascending  curve  instead  of  the  straight  line  that  might  have 
been  expected. 

A  glance  at  Figure  I,  showing  graphically  the  results  of  sub¬ 
ject  H.  R.  K.,  which  are  typical  for  the  first  group  of  experi¬ 
ments,  will  make  the  situation  clear.  The  numbers  on  the  ordinate 
refer  to  positions  on  the  scale  in  centimeters,  and  those  on  the 
abscissa  to  successive  days’  sittings.  The  four  straight  lines  at 
53,  66,  79,  and  92  represent  the  actual  positions  of  the  4  buzzers. 
Buzzer  number  1  (53)  is  to  the  subject’s  right;  buzzer  number  4 
(92)  to  his  left  as  he  sits  at  the  apparatus.  The  curves  which 
approach  the  lines  show  the  progress  of  the  subject  from  day 
to  day,  each  point  on  a  curve  representing  the  average  of  the 
five  trials  for  that  buzzer  taken  on  that  day.  The  line  and  curve 
for  buzzers  92  (4)  and  66  (2)  are  dotted,  while  those  for  79 
(3)  and  53  (1)  are  unbroken. 

In  seeking  for  a  method  of  treatment  of  the  results  which  should 
be  suitable  for  all  the  series  of  experiments  in  our  investigation,  we 
finally  decided  on  the  following  plan.  The  measure  of  the  amount 
of  readjustment  effected  in  any  case  is  the  distance  in  centimeters 
still  “unrecovered”  when  the  subject  has  reached  his  highest  point 
of  readjustment.  In  the  case  of  any  subject,  then,  this  distance  will 
be  obtained  for  each  buzzer  by  substracting  the  average  of  the 
five  localizations  made  at  the  highest  point  of  readjustment,  from 
the  average  of  the  five  trials  for  normal  visual  accuracy  made  for 
the  same  buzzer.  This  will  give  the  number  of  centimeters  that 
would  have  to  be  “recovered”  before  the  subject  would  again 
attain  his  normal  accuracy  in  localizing  the  buzzer.  Such  a  linear 
distance  yet  remaining  to  be  “recovered”  we  will  call  arbitrarily 
in  our  discussion  of  results,  “the  remainder.”  For  example  sub¬ 
ject  H.  R.  K.,  beginning  with  a  linear  deviation  of  about  25  cm. 
for  buzzer  number  1,  had  reached  as  her  high  point  of  readjust- 


THE  DEVELOPMENT  OF  A  NEW  SPATIAL  CO-ORDINATION  17 


Fig  I.  Readjustment  of  Subject  H.  R.  K.  Standard  Series 


ment  for  that  position,  on  the  19th  day’s  sitting,  the  average 
position  of  44.5  cm.  Her  average  normal  localization  for  buzzer 
1  ls  55-5  cm-  Her  remainder  for  buzzer  1,  then,  for  the  whole 
period  of  the  series,  is  55.5  cm.  minus  44.5  cm.,  or  n  cm. 

In  addition  to  thus  measuring  the  amount  of  readjustment  by 
the  remainder,  or  remaining  distance  from  the  normal  standard 
of  accuracy,  it  is  also  convenient  at  times  to  use  as  a  measure  the 
per  cent  of  the  linear  deviation  which  has  already  been  recovered. 
Such  a  measure  is,  however,  far  less  significant  for  comparative 
discussion  than  the  remainder,  for  the  reason  that  it  is  based  on 


i8 


MARGARET  WOOSTER 


the  initial  linear  deviation,  which  varies  greatly  among  indivi¬ 
duals. 

While  theoretically  the  glasses  should  produce  a  standard  ob¬ 
jective  linear  deviation  which  is  the  same  for  all  individuals, 
practically,  under  the  conditions  of  our  experiment,  they  do  not. 
This  is  because  in  the  first  place  the  position  of  the  head  is  not 
constant,  and  the  linear  deviation  varies  somewhat  with  every 
change  in  the  distance  from  the  buzzer  to  the  eye,  and  in  the 
angle  formed  by  this  line  with  the  scale  at  the  back  of  the  ap¬ 
paratus  along  which  the  linear  deviation  is  measured.  It  was  not 
possible  to  keep  these  factors  constant  by  fixing  the  head  posi¬ 
tion,  because  among  the  series  is  one  involving  auditory  localiza¬ 
tion,  for  which  free  head  movement  is  essential;  and  general 
conditions  had  to  be  constant  throughout  the  experimental  series. 

A  second  reason  for  individual  variation  in  linear  deviation 
may  be  found  in  the  variability  of  the  angle  of  incidence  or  the 
angle  at  which  the  rays  of  light  from  the  buzzer  strike  the  prisms. 
According  as  the  buzzer  is  viewed  through  the  large  or  the  small 
end  of  the  prisms,  there  is  a  difference  of  several  centimeters  in 
linear  deviation.  As  a  matter  of  fact  with  the  direct  forward 
fixation  which  was  naturally  maintained  in  localizing  the  buzzers 
the  change  due  to  variation  in  angle  of  incidence  would  be  so 
slight  as  to  be  practically  negligible.  It  must  be  reckoned  with, 
however,  as  a  factor  tending  to  produce  a  slight  amount  of  varia¬ 
tion  from  individual  to  individual  as  well  as  within  the  results 
of  any  one  subject. 

Thus  it  is  impossible  to  determine  a  standard  general  linear 
deviation  upon  which  to  base  per  cents  of  readjustment  for  all 
subjects.  It  might  seem  practicable  to  base  the  per  cents  of  read¬ 
justments  for  an  individual  on  his  own  initial  linear  deviation. 
But  it  is  not  possible  closely  to  determine  even  this  individual 
deviation.  Several  trials  would  be  needed  for  a  reliable  determina¬ 
tion.  Readjustment,  however,  begins  after  the  very  first  trial, 
and  indeed  in  some  series  even  prior  to  it.  Again,  the  head  posi¬ 
tion  even  of  one  individual,  may  change  somewhat  from  trial  to 
trial  for  the  same  buzzer. 

It  is  clear,  then,  that  for  purposes  of  group  comparison  the 


THE  DEVELOPMENT  OF  A  NEW  SPATIAL  CO-ORDINATION  19 


remainder,  rather  than  the  per  cent  of  readjustment,  is  the  more 
reliable  measure  of  progress.  It  will  be  helpful,  however,  to  deal 
with  per  cents  in  treating  individual  results,  and  in  broad  general 
discussions. 

To  find  the  per  cent  of  readjustment  for  any  individual  we 
must  find  the  total  distance  between  the  initial  localization  with 
the  glasses  and  the  place  of  normal  localization,  and  determine 
what  per  cent  of  that  distance  has  been  recovered  at  the  highest 
point  of  readjustment.  In  the  first  two  series,  A  and  B,  the  five 
localizations  of  a  buzzer  in  the  first  sitting  are  about  the  same, 
and  so  to  find  the  initial  deviation  for  individuals  in  those  series 
we  will  subtract  the  average  of  the  first  five  trials  for  a  given 
buzzer,  from  the  average  of  the  10  trials  for  normal  accuracy 
of  localization  of  the  same  buzzer. 

In  series  C,  D,  and  E,  however,  readjustment  is  so  rapid  that 
the  average  for  the  first  five  trials  for  a  position  would  already 
represent  an  advance  of  as  much  as  several  centimeters  over  the 
initial  localization  for  that  position.  Hence  in  these  later  groups 
we  are  compelled  to  find  the  initial  deviation  for  a  given  posi¬ 
tion  by  subtracting  the  first  trial  only  from  the  average  normal 
localization.  This  will  mean  greater  variability  in  linear  devia¬ 
tions,  since  one  trial  is  not  a  sufficient  measure  of  accuracy.  Here 
too  there  will  be  considerable  variability  in  the  amount  of  initial 
deviation  for  the  four  different  positions,  owing  to  the  fact  that 
readjustment  is  already  in  progress  after  the  first  localization 
among  these  four.  For  the  last  three  series,  then  (C,  D,  and  E), 
since  the  per  cent  of  readjustment  based  on  initial  deviation  will 
be  particularly  variable  and  thus  unreliable  for  comparative  pur¬ 
poses,  the  usual  basis  of  comparative  discussion  will  be  the  re¬ 
mainder. 

Individual  and  group  results  for  series  A-i-a  are  given  in 
Figures  I  and  II  and  in  Table  I  (p.  20).  Nine  subjects  in  all 
served  in  this  group.  This  includes  the  writer  whose  peculiar 
knowledge  of  the  situation  makes  her  results  not  strictly  com¬ 
parable  with  the  others,  and  one  subject  who  was  forced  early 
to  discontinue  the  sittings.  This  leaves  seven  whose  results  are 
considered  in  computing  group  averages. 


20 


MARGARET  WOOSTER 


TABLE  I 

Standard  Series 

Showing  results  for  Group  A-ia  ( with  knowledge )  and  Group  A-i-b 

( without  knowledge ) 


Sub-  No.  Visual  Acc.  Av.*l.d.  Av.  Ay.  Per  centPer  cent 

jects  of  Sit-  -  ist  5  Rem.  Rem.  Readj.  Readj. 

tings  53  66  79  92  trials  10  da.  Total  I0  <ja.  Total 


Group  A-i-a 

H.L.K.  12  55.1  69.3  82.7  94.7  18.7  9-9  8-8  47  53 

M.R.G.  25  52.8  65.7  79.5  92.7  20.7  12.5  12.2  40  41 

O. B.B.  22  52.8  65.7  79.2  92.7  20.5  16.9  9.5  18  54 

H.R.K.  23  55.5  65.5  78.8  92.4  21.9  14.7  9.7  33  56 

M.F.R.  19  53.6  67.7  81.0  93.8  18.4  11. 7  8.7  37  53 

W.A.O.  2 7  55-7  68.4  81. 1  93.1  16.8  9.4  3-5  44  79 

P. R.  10  .  17.1  12.4  _  28 

Average  54.2  67.0  80.4  93.2  19.1  12.5  8.7  35  56 


Group  A-i-b 

M.O.W.  28  16.9  13.7  10.6  19  37 

D.S.  15  22.6  9.8  9.7  56  57 

R.R.  11  12.4  7-8  7-5  37  40 

M.McF.  35  18.9  1 1.3  8.6  41  54 

Average  .  17.7  10.6  9.1  38  47 


*  l.d. — linear  deviation. 

The  four  curves  of  H.  R.  K.,  presented,  as  typical  ones,  in 
Figure  I,  show  a  gradual  and  steady  slope,  extending  over  16 
days’  sittings,  after  which  for  eight  days  there  is  only  a  slight 
wavering  with  no  improvement.  There  is  a  striking  correspond¬ 
ence  in  the  shape  of  the  curves  for  the  four  buzzers,  a  slight 
change  in  one  curve  for  a  day’s  sitting  almost  always  correspond¬ 
ing  to  a  similar  change  in  the  other  three  curves.  These  facts  indi¬ 
cate  that  whatever  causes  are  at  work  to  produce  the  “learning,” 
operate  in  a  regular  and  consistent  manner.  The  relatively  straight 
line  from  the  16th  to  the  23d  sitting  seemed  at  the  time  to  in¬ 
dicate  that  the  subject  had  reached  the  limit  of  improvement,  and 
so  the  sittings  were  discontinued.  Later  experiments  would  in¬ 
dicate  that  this  may  have  been  only  a  “plateau,”  and  that  another 
period  of  improvement  might  have  set  in.  The  drop  in  the  curves 
at  the  fifth  sitting  may  have  been  due  to  the  unusual  fatigue 
reported  by  the  subject  at  that  time.  Of  her  initial  linear  devia- 


THE  DEVELOPMENT  OF  A  NEW  SPATIAL  CO-ORDINATION  21 


tion  of  22  cm.,  Table  I  shows  that  H.  R.  K.  recovered  finally  56 
per  cent,  with  a  final  remainder  of  9.7  cm. 

Questioning  at  the  close  of  the  series  with  distorted  vision 
revealed  the  fact  that  H.  R.  K.,  while  aware  that  the  distortion 
was  to  the  right  of  the  actual  position  of  the  buzzers,  was  not 
aware  either  of  the  extent  of  her  error  or  of  the  fact  that  she 
was  gradually,  as  the  sittings  progressed,  reacting  farther  and 
farther  to  the  left.  She  could  imagine  no  factors  that  could  have 
caused  her  thus  to  change  her  localizations,  beyond  the  mere 
fact  of  knowledge  of  the  direction  of,  the  distortion. 

Similar  in  type  to  the  results  of  H.  R.  K.  are  those  of  H.  L.  K., 
M.  R.  G.,  and  M.  F.  R.  The  curves  for  all  of  them  (not  given 
in  the  figure)  show  the  same  gradual  and  steady  progress  and 
the  same  correspondence  in  the  curves  for  the  four  buzzers. 
They  differ  in  rate  and  amount  of  readjustment  effected,  M.  R. 
G’s  progress  being  very  slow  and  amounting  to  only  41  per  cent  of 
recovery  of  his  initial  deviation  after  25  sittings,  while  H.  L.  K’s 
progress  (the  most  rapid  in  the  group)  amounted  to  53  per  cent 
of  her  initial  deviation  in  the  course  of  only  12  sittings.  If  it 
had  been  possible  to  continue  H.  L.  K’s  sittings,  it  seems  likely 
that  she  might  have  finally  entirely  overcome  her  remainder  of 
nine  cm.,  although  it  is  true  that  for  the  last  five  of  her  sittings 
she  showed  no  improvement. 

The  results  of  two  subjects  in  this  group,  O.  B.  B.  and  W. 
A.  O.,  require  special  discussion.  They  are  presented  graphically 
in  Figure  II.  In  this  figure  as  in  succeeding  figures  only  two  curves 
are  shown  although  curves  for  all  four  buzzers  were  originally 
plotted.  The  curves  for  the  four  positions  are  so  nearly  alike 
that  it  was  not  thought  necessary  to  present  them  all  here.  In  each 
case,  then,  curves  for  buzzer  No.  1  (53)  and  buzzer  No.  4  (92) 
only  are  given  (except  for  Figure  III  where  curves  for  No.  2  and 
No.  4  are  given).  These  two  are  taken  because  of  the  four  they 
differ  most  widely  in  the  case  of  practically  all  subjects.  (It  will  be 
noted  that  the  curves  for  buzzer  No.  4  almost  universally  show  rel¬ 
atively  closer  approach  to  the  actual  position  of  the  buzzer,  than 
curves  for  buzzer  No.  1.  In  general  the  farther  to  the  left  the 
buzzer,  the  greater  the  degree  of  the  apparent  readjustment  as 


22 


MARGARET  WOOSTER 


indicated  by  the  curves.  This  fact  can  be  explained  on  mathemati¬ 
cal  grounds,  as  set  forth  in  the  discussion  of  experiment  A-2-b,  on 
page  42.  In  this  figure  the  numbers  on  the  abscissa  again  refer 
to  the  numbers  of  the  sittings,  but  the  numbers  on  the  ordinate 
represent  this  time  the  number  by  which  the  localizations  for  each 
day  deviate  on  the  average  from  the  true  position  of  the  buzzer, 
indicated  by  the  straight  dotted  line.  Thus  the  curves  show  from 
day  to  day  a  gradually  decreasing  deviation.  In  every  curve  pre¬ 
sented  in  the  figure  the  first  point,  for  the  first  day’s  sitting  rep¬ 
resents  the  deviation  of  the  actual  initial  localization  for  that 
particular  buzzer,  and  not  the  average  of  the  five  trials  for  that 
day.  This  is  done  to  give  a  true  idea  of  the  actual  range  of 
the  deviation.  A  truer  picture  of  succeeding  progress,  however, 
because  more  measurements  are  considered,  is  given  by  letting  the 
point  for  each  day  represent  the  average  of  the  five  trials  for  that 
day,  and  so  the  second  and  succeeding  points  on  the  curves 
each  represent  the  average  of  five  trials  for  a  particular  day’s 
sitting. 

The  method  of  plotting  used  in  Figure  II  holds  for  all  the  suc¬ 
ceeding  figures  except  for  III  and  IV  where  special  exceptions 
are  noted.  It  will  help  in  understanding  the  figures  to  remember 
that  the  lower  curves  represent  buzzer  1,  or  position  53  on  the 
scale,  to  the  subject’s  right;  and  that  the  upper  curves  represent 
buzzer  4,  or  position  92  on  the  scale,  to  the  subject’s  left. 

The  results  of  O.  B.  B.  are  peculiar,  in  that  unlike  the  other 
subjects  discussed  his  improvement  was  not  gradual  and  steady 
from  sitting  to  sitting.  In  his  case,  after  a  short  rise  from  the 
first  to  the  third  sittings,  the  curves  settle  down  into  relatively 
straight  lines  showing  no  further  improvement  until  the  12th 
sitting,  after  which  they  rise  rapidly  to  the  17th  before  terminat¬ 
ing  in  the  five  day  “plateau”  which  may  or  may  not  mark  the 
limit  of  improvement.  Reference  to  Table  I  shows  that  while 
within  the  first  10  sittings  his  average  remainder  was  as  large  as 
16.9  out  of  an  average  initial  deviation  of  20.5,  by  the  end  of 
the  22d  sitting  it  was  only  9.5.  Otherwise  stated,  for  the  first  10 
sittings  the  readjustments  effected  was  only  18  per  cent,  but  at 
the  17th  sitting  it  had  jumped  to  54  per  cent.  It  is  results  like 


THE  DEVELOPMENT  OF  A  NEW  SPATIAL  CO-ORDINATION  23 


Fig.  II.  Standard  Series.  With  Knowledge. 


24 


MARGARET  WOOSTER 


these  of  0.  B.  B.  which  first  made  the  experimenter  doubt  the 
validity  of  any  criterion  for  deciding  when  a  subject  has  reached 
the  limit  of  adjustment.  Later  results  in  this  and  other  series 
confirmed  this  doubt  and  suggested  that  in  every  case  there  was 
a  genuine  possibility  that  if  the  subject  only  kept  on  long  enough, 
he  would  finally  completely  readjust  himself  to  the  new  visual 
situation. 

O.  B.  B’s  comments  as  the  sittings  progressed  are  suggestive. 
Remember  that  there  were  no  obvious  clues  by  which  he  could 
judge  the  position  of  his  finger  at  any  localization.  In  the  first 
sittings  he  reports  feeling  very  uncertain  and  “helpless”  while 
reaching  out.  From  the  ninth  sitting  on  he  reported  feeling  more 
confident,  although  he  didn’t  know  why  he  should  be.  At  the 
12th  sitting  (when  in  fact  the  first  objective  indication  of  the 
rapid  rise  appears)  he  reports  “Feel  at  home  now — not  lost  as 
I  was  at  first,”  and  “I  bet  you  I  am  not  far  off  from  the  true 
position.”  (As  a  matter  of  fact  he  was  still  16  cm.  off!) 

At  the  1 8th  sitting  when  he  had  reached  his  smallest  remainder 
(9.5  cm.),  he  reports  “I  feel  perfectly  at  home,  but  don’t  know 
what  I’m  doing.”  When  questioned  at  the  end  of  the  experiment, 
he  was  unable  to  state  just  what  made  him  feel  as  he  did.  While 
aware  of  the  fact  that  his  manner  of  localization  was  changing, 
he  had  not  been  conscious  of  the  clues  on  the  basis  of  which 
this  change  in  reaction  occurred. 

The  other  peculiar  case  calling  for  separate  consideration  is 
that  of  subject  W.  A.  O.  These  curves  rise,  not  smoothly,  but  in 
a  rather  zigzag  fashion,  until  at  the  16th  sitting  the  average 
remainder  is  only  3.5  cm.,  and  for  two  of  the  buzzers  the  curve 
actually  meets  the  line,  showing  complete  readjustment  for  these 
positions.  This  is  unusual  progress.  But  the  peculiar  thing  is  that 
at  this  point  the  curves  begin  to  descend  again,  until  by  the  26th 
sitting  W.  A.  O.  has  apparently  unlearned  all  that  he  learned! 
By  this  time  he  is  again  within  five  centimeters  of  his  initial 
deviation. 

The  subject’s  comments  as  the  sittings  progressed  may  help  to 
explain  this  unusual  situation.  During  the  fourth  sitting  (which 


THE  DEVELOPMENT  OF  A  NEW  SPATIAL  CO-ORDINATION  25 

marks  a  high  point  in  the  curves)  he  says  “I  feel  more  and  more 
confidence  that  I  am  hitting  these,  but  don’t  know  its  source.” 
At  the  next  sitting  (fifth)  he  reports  that  he  knows  the  direction 
of  the  error — to  the  right.  Once  in  awhile  he  has,  because  of 
leaning  farther  back  from  the  table,  obtained  a  glimpse  of  his 
sleeve  and  the  direction  of  his  arm  in  reaching  out  for  the  buzzer. 
This  gave  him  the  clue.  He  has  also  seen,  two  or  three  times, 
the  beginning  of  the  experimenter’s  movement  to  the  right  to  note 
the  position  of  his  finger.  At  the  16th  sitting  (the  point  of  great¬ 
est  readjustment)  the  report  is  “The  thing  seems  much  more 
natural.  Distances  to  the  right  don’t  seem  so  long,  or  to  the  left 
so  short,  as  at  first  .  .  .  This  leads  me  to  think  I’m  adjusting 
or  learning  to  react  naturally.”  But  this  “natural”  reaction  he 
thought  was  to  a  point  in  each  case  a  good  number  of  centimeters 
to  the  right  of  where  the  buzzers  actually  were.  With  the  17th 
sitting  the  downward  slope  begins.  At  the  18th,  21st,  and  22d 
sittings  he  reports  being  unusually  tired  and  sleepy — “Am  con¬ 
sistently  getting  too  little  sleep  these  nights.”  At  the  22d  sit¬ 
ting  he  speaks  of  having  been  self-conscious  lately  and  more  un¬ 
certain  because  of  hearing  remarks  from  the  experimenter  and 
Professor  X  about  his  “queer”  record.  At  the  23d  sitting  he  says 
“I  feel  that  I  am  doing  well.  I  reach  to  the  right  so  it  feels  a 
long  distance — that’s  the  way  it  has  been  feeling — it  seems  farther 
than  it  looks.” 

Now  on  the  face  of  it,  it  would  appear  that  W.  A.  O.  was 
influenced  unconsciously  by  the  mere  knowledge  of  the  fact 
of  deviation  to  the  right,  gradually  to  approach  the  actual  posi¬ 
tion  of  the  objects,  until  he  had  practically  overcome  the  deviation. 
At  this  point  (16th  sitting)  he  reported  such  confidence  in  the 
naturalness  of  the  reactions  that  the  experimenter  questioned  him 
more  closely  than  she  usually  questioned  subjects,  concerning  the 
extent  to  which  he  had  been  following  the  directions  to  ignore 
the  fact  of  distortion.  This,  it  would  seem,  made  him  self- 
conscious;  and  when  on  the  next  day  his  fatigue  caused  a 
natural  slump  in  the  curves,  the  fact  that  he  thought  the  ex¬ 
perimenter  “seemed  worried”  at  his  record,  increased  his  self- 


26 


MARGARET  WOOSTER 


consciousness.  From  this  point  his  determination  conscientiously 
to  ignore  the  distortion  to  the  right  simply  meant  that  it  was 
emphasized  in  his  mind,  and  his  later  reactions  were  influenced 
by  the  unconscious  tendency  to  react  farther  to  the  right  than  he 
had  been  reaching.  Whether  or  not  this  is  the  true  explanation 
is  a  question. 

Consideration  of  group  A-i-a  as  a  whole  brings  out  some  in¬ 
teresting  points.  In  the  first  place  while  a  general  tendency  to  build 
up  a  new  spatial  coordination  is  apparent,  there  are  well  marked 
individual  differences.  Of  those  who  did  show  a  decided  readjust¬ 
ment,  the  amount  varied  from  an  average  total  remainder  of  12.2 
in  the  case  of  M.  R.  G.  to  as  little  as  3.5  in  the  case  of  W.  A.  O. 
One  subject,  the  writer,  showed  only  a  small  amount  of  wavering 
in  her  curves,  and  no  definite  tendency  whatever  to  readjust. 
Another  subject,  P.  A.  R.,  made  no  really  significant  advance 
within  the  10  sittings  he  took,  and  it  is  a  question  whether  like 
O.  B.  B.  he  would  have  shown  a  spurt  of  progress  later  had  he 
continued  the  experiments.  Speaking  in  terms  of  per  cents  of 
readjustment,  of  the  eight  subjects  who  continued  presumably 
up  to  the  limit  of  improvement,  six  showed  a  per  cent  of  read¬ 
justment  of  over  50,  while  one  attained  only  41  per  cent  and  one 
(the  writer)  remained  at  zero  percent.  The  highest  per  cent  was 
79  and  the  average  total  per  cent  was  56.  The  average  per  cent 
for  the  10  day  period  was  37. 

Not  only  in  amount  but  also  in  rate  of  adjustment  are  marked 
individual  differences  apparent.  While  in  general  the  curves 
show  a  rapid  increase  for  the  first  three  sittings  and  then  a  gradual 
increase  up  to  the  “plateau”  which  terminated  the  sittings,  one  set, 
those  of  O.  B.  B.,  shows  after  the  initial  rise  a  long  level  stretch 
and  then  a  sudden  rise.  Another,  that  of  W.  A.  O.,  exhibits  a 
gradual  but  quick  approach  and  then  a  retrogression.  One  set  of 
curves,  those  of  M.  R.  G.,  drags  out  over  25  sittings  and  then 
shows  a  readjustment  of  only  53  per  cent.  H.  L.  K’s  per  cent 
within  a  10  day  period  is  47,  while  O.  B.  B’s  is  within  the  same 
period  only  18. 

It  remains  now  to  consider  to  what  extent  the  subjects  were 
aware  of  the  direction  and  amount  of  the  deviation  and  what 


THE  DEVELOPMENT  OF  A  NEW  SPATIAL  CO-ORDINATION  27 

may  have  been  the  effect  of  their  attitude  toward  the  experiment. 
In  the  first  place  all  knew  that  the  direction  of  the  deviation  was 
to  the  right.  At  least  one  knew  before  starting,  through  noticing 
the  position  of  the  prisms  in  the  frame,  but  most  of  them  be¬ 
came  aware  of  it  only  after  the  sittings  were  under  way,  through 
noticing  the  change  in  length  of  the  reach  to  the  right,  as  com¬ 
pared  with  the  corresponding  movement  in  the  previous  normal 
series.  All  conscientiously  aimed  to  ignore  this  fact  of  distortion 
in  making  their  localizations,  and  some  were  unaware  that  they 
were  making  any  readjustment.  M.  R.  G.,  for  instance,  who  esti¬ 
mated  quite  well  the  extent  of  his  initial  error,  drew  a  diagram 
after  his  seventh  sitting  to  show  that  he  must  be  hitting  in  the 
same  place  each  time.  Most  of  the  subjects  felt  each  time  that  the 
finger  was  just  beneath  the  buzzer.  In  this  respect  H.  L.  K.  is  an 
exception.  When  she  was  making  a  localization  it  seemed  to  her 
that  she  was  touching  the  right  place,  but  as  soon  as  she  closed  her 
eyes  her  finger  seemed  out  of  place.  Toward  the  end  of  her  sittings 
she  reported  feeling  more  natural — that  her  finger  seemed  less 
out  of  place.  This  is  due  to  the  fact  that  when  she  first  started 
she  retained  the  kinaesthetic  set  from  the  preceding  series,  and 
felt  clearly,  as  most  of  the  other  subjects  did  not,  the  difference 
between  that  and  the  different  “feel”  due  to  the  deviation  to  the 
right.  It  is  of  interest  here  to  note  that  H.  L.  K’s  progress  was 
the  most  rapid  in  the  group.  A.  S.  F.,  who  after  the  quick  read¬ 
justment  of  about  eight  centimeters  in  six  sittings  had  to  dis¬ 
continue  the  experiment,  reported  “I  feel  that  the  desire  to  correct 
to  the  left  influences  me,  although  I  try  to  ignore  it.”  She  is  the 
only  one  to  report  such  a  feeling. 

The  results  of  the  first  series  of  experiments  seemed  to  indicate 
that  knowledge  of  the  direction  and  extent  of  the  deviation  might 
well  be  the  chief  factor  in  the  process  of  readjustment.  We  de¬ 
cided,  then,  to  give  the  same  series  to  a  group  of  subjects  so 
chosen,  and  with  experimental  conditions  so  arranged,  as  to  ex¬ 
clude,  if  possible,  every  source  of  knowledge  of  the  nature  of  the 
deviation.  The  possible  sources  of  knowledge  in  the  series  as 
first  given,  A-i,  together  with  the  way  in  which  these  were 


28 


MARGARET  WOOSTER 


obviated  with  the  second  group  of  subjects,  in  A-2,  we  will  dis¬ 
cuss  point  by  point. 

1.  A  knowledge  of  the  direction  and  extent  of  the  deviation 
might  be  gained  from  other  subjects  who  had  finished  the 
series  and  knew  of  the  conditions.  This  was  avoided  in  both 
A- 1  and  A-2  by  strictly  cautioning  each  subject  not  to  discuss 
the  experiment  with  others. 

2.  The  subject  might  gain  such  a  knowledge  through  noticing 
the  sudden  shift  to  the  right  in  the  position  of  objects  at  the 
moment  of  putting  on  the  glasses.  In  A-i  this  was  avoided  by  hav¬ 
ing  the  subject  turn  away  from  the  table  and  close  his  eyes  while 
the  glasses  were  being  put  on.  In  A-2  the  additional  precaution 
was  observed  of  having  the  subject  led  about  the  room  with 
eyes  closed  and  then  seated  in  a  chair  facing  in  a  direction  dif¬ 
ferent  from  that  in  which  he  had  previously  faced,  before  the 
glasses  were  put  on  and  before  he  was  permitted  to  open  his  eyes. 

3.  Knowledge  might  be  gained  through  a  comparison  of  the 
apparatus  or  general  surroundings  as  viewed  through  the  glasses, 
with  their  remembered  appearance  without  the  glasses.  In  A-2 
this  possibility  was  obviated  by  taking  as  subjects  only  such  stu¬ 
dents  as  had  never  been  inside  the  experimenter's  room,  seen  the 
apparatus,  or  heard  it  described.  Hence  since  the  glasses  were 
put  on  and  taken  off  in  another  room,  these  subjects  had  neither 
directly  nor  from  the  report  of  others  any  knowledge  of  the  nor¬ 
mal  appearance  of  the  apparatus  or  the  room. 

4.  The  subject  might  learn  the  nature  of  his  error  through 
noticing  the  position  assumed  by  the  experimenter  in  bending  over 
to  get  the  record,  either  through  accidentally  opening  his  eyes  or 
through  a  too  quick  movement  of  the  experimenter  before  the 
eyes  were  closed.  To  obviate  this  source  of  knowledge  the  black 
curtain  previously  described  was  used  to  screen  the  experimenter’s 
movements  while  taking  the  record. 

5.  The  subject  might  discover  the  direction  of  the  distortion 
through  retention  of  the  kinaesthetic  set  from  either  the  previous 
normal  series  or  the  auditory  series,  and  its  comparison  with  the 
new  set  due  to  the  deflection  to  the  right.  This  comparison  was 


THE  DEVELOPMENT  OF  A  NEW  SPATIAL  CO-ORDINATION  29 


indeed  reported  as  the  source  of  such  knowledge  by  some  of  the 
subjects  in  A-i.  In  A-2  such  a  possibility  was  provided  against 
by  having  the  subject  start  in  with  the  main  series,  omitting  the 
preliminary  tests  without  the  glasses. 

6.  Again,  the  unnaturally  long  reach  to  the  right  might  sug¬ 
gest,  even  were  there  no  preliminary  tests,  that  the  distortion 
was  in  that  direction.  To  eliminate  this  possibility  in  A-2,  the 
extreme  right  hand  buzzer  which  involved  the  only  long  reach 
upon  which  subjects  had  commented,  was  omitted.  This  left  only 
three  buzzers  to  be  localized. 

7.  A  seventh  possibility  is  that  the  subject  familiar  with  the 
effect  of  prisms  might  easily  reason  out  both  the  direction  and 
the  approximate  extent  of  the  deviation,  through  the  mere  ob¬ 
servation  of  the  prisms  before  putting  on  the  glasses.  In  A-2 
this  possibility  was  obviated  by  not  permitting  the  subject  to  see 
the  glasses  at  any  time,  and  by  making  sure  before  the  sittings 
began  that  he  had  not  heard  from  any  source  what  kind  of  glasses 
were  being  used. 

8.  Finally,  the  subject  might  gain  knowledge  of  the  character 
of  the  deviation  through  his  unusual  tactual-kinaesthetic  orienta¬ 
tion  with  respect  to  the  edge  of  the  table  and  the  cover.  In  other 
words  through  feeling  of  these  edges  as  he  sat  looking  at  the 
buzzers  he  might  find  out  that  the  line  of  vision  was  not  perpen¬ 
dicular  to  these  edges  as  he  might  expect,  but  one  forming  an 
angle  to  the  right.  The  same  sort  of  clues  might  be  gained  for 
some  subjects  from  the  contact  of  the  lower  part  of  the  board 
forming  the  front  of  the  table,  with  the  body  or  the  knees.  In 
order  to  eliminate  these  possible  clues,  several  precautions  were 
taken.  The  lower  section  of  the  front  board  was  sawed  out  in 
order  to  prevent  contact.  The  subject  was  strictly  forbidden  to 
make  exploratory  movements  with  his  hands  between  trials. 
At  the  beginning  of  the  sitting  the  experimenter  put  the  sub¬ 
ject’s  hands  in  position  in  front  of  him.  The  first  paragraph  of 
the  “Instructions  to  Subject”,  covering  this  point,  is  as  follows: 

“When  seated  in  the  chair,  let  the  right  arm  lie  along  the  edge 
of  the  table,  and  the  left  extend  out  on  the  table,  but  not  more 
than  90  degrees  to  the  left.  Between  trials  either  keep  the  arms 


30 


MARGARET  WOOSTER 


in  this  position,  or  swing  the  chair  away  from  the  table  and 
let  them  rest  in  your  lap.  At  no  time  make  any  exploratory  move¬ 
ments  except  when  directed  to.” 

The  eight  sources  of  knowledge  discussed  above  include  all 
possible  ways,  we  think,  in  which  the  subject  might  gain  a  knowl¬ 
edge  of  the  direction  and  extent  of  the  deviation  produced  by  the 
glasses.  They  were  all  eliminated  in  the  series  as  given  to  the 
second  group  of  subjects — series  A-2.  This  does  not  necessarily 
mean,  of  course,  the  elimination  of  all  possible  sensory  clues  on 
the  basis  of  which  the  subject  might  unconsciously  react. 

b.  Experiments  Without  Knowledge. 

Aside  from  the  paragraph  quoted  above,  and  a  sentence  ex¬ 
plaining  the  use  of  the  curtain,  the  instructions  for  Series  A-i-b 
were  exactly  as  in  A-i.  The  glasses  were  put  on  the  subject  in 
the  manner  described,  in  an  outer  room.  He  was  then  led  into  the 
experimenter’s  room  and  to  the  subject’s  chair,  in  which  he 
managed  to  seat  himself  by  the  aid  of  touch  and  kinaesthesis. 
When  his  hands  had  been  put  in  position  by  the  experimenter 
he  was  permitted  to  open  his  eyes.  He  then  began  the  localizations 
according  to  the  instructions  he  had  received.  In  order  that  these 
instructions  might  be  thoroughly  impressed  upon  the  subject, 
they  were  typewritten  and  he  was  required  to  study  them  before 
each  of  the  first  three  sittings. 

The  trials  were  given  in  the  same  manner  as  in  A-i  except  for 
the  use  of  the  curtain.  Since  only  three  buzzers  were  used  seven 
trials  each  were  given  in  a  sitting.  This  makes  the  total  number 
of  trials  and  of  minutes  21  instead  of  20,  but  such  a  small  differ¬ 
ence  could  hardly  be  expected  to  have  any  appreciable  influence  on 
the  results. 

At  the  conclusion  of  the  sitting  the  subject  was  led  out  of  the 
room  with  eyes  closed.  He  was  not  permitted  to  open  his  eyes 
until  the  glasses  had  been  removed  and  put  out  of  sight. 

Individual  results  for  this  series  are  given  in  Table  I,  p.  20. 
In  Figure  III  are  presented  two  typical  sets  of  curves,  those  of 
subjects  D.  S.  and  M.  O.  W.  Since  in  this  series  buzzer  No.  1 


THE  DEVELOPMENT  OF  A  NEW  SPATIAL  CO-ORDINATION  31 


was  not  used,  the  two  curves  given  for  each  subject  are  for  buz¬ 
zers  2  and  4. 

These  results  are  surprising.  The  subjects  in  this  group, 
although  in  at  least  three  cases  ignorant  by  their  own  later  state- 


NirrrTftY  of-  SlTt’lYv.^ 

Fig.  III.  Standard  Series.  Without  Knowledge. 

ments  of  the  nature,  direction,  or  extent  of  the  distortion,  showed 
during  the  first  10  days  just  as  marked  a  tendency  to  readjust  to 
the  new  visual  situation  as  did  the  subjects  in  the  first  group! 
In  fact  if  we  were  to  consider  significant  the  small  difference 
in  amount  of  readjustment,  they  showed  in  the  first  10  days  more 
of  a  tendency,  for  on  the  average  their  remainder  is  only  10.6 
cm.,  while  the  average  for  the  first  group  is  12.5  cm.  Even  this 
small  difference  decreased  with  later  sittings,  and  so  allowing  for 
the  slight  variation  in  the  experimental  conditions,  the  logical 
conclusion  would  be  that  knowledge  of  the  conditions  of  the 
distortion  apparently  has  no  effect  either  on  the  rapidity  or  the 
rate  of  the  readjustment.  Comparison  of  the  average  curves 


32 


MARGARET  WOOSTER 


for  io  days  of  these  two  groups,  as  shown  in  Figure  X  reveals 
their  essential  similarity. 

The  curves  for  this  group  show  the  same  consistency  and  the 
same  sort  of  individual  differences  as  in  the  first  group.  The  two 
longest  curves  in  the  group,  those  of  M.  M.  and  M.  O.  W.,  show 
continuous  and  very  gradual  progress,  extending  over  28  and 
35  days  respectively.  M.  M/s  results,  with  41  per  cent  of  im¬ 
provement  within  10  days  and  54  per  cent  within  35  days, 
especially  seem  to  indicate  that  improvement  may  go  on  in¬ 
definitely. 

The  comments  of  individuals  are  of  interest  here.  R.  R.  re¬ 
ports  that  she  did  not  know  at  all  the  direction  of  the  distortion, 
though  she  had  a  vague  feeling  that  it  was  to  the  left.  “I  hadn’t 
the  slightest  idea  as  to  the  kind  of  lenses — I  felt  I  was  to  the 
right  but  didn’t  know  why  at  all — thought  my  finger  was  about 
one  inch  to  the  right  of  the  buzzer  ...  I  felt  I  was  hitting  in 
the  same  place  all  the  time  .  .  .For  the  first  few  sittings  my 
finger  didn’t  feel  right.  Later  the  finger  felt  just  where  it  landed.” 

Early  in  the  series  M.  O.  W.  found  out  that  there  was  some 
sort  of  disparity  from  seeing  the  experimenter  in  one  place  when 
she  went  to  the  door  and  “hearing  her  talk  in  another.”  But  at 
the  eighth  sitting  he  reports  “I  don’t  know  what  these  things 
(glasses)  are  doing.  For  all  I  know  you  may  even  be  behind  me, 
and  everything  turned  clear  around.”  It  was  only  at  the  18th 
sitting  that  M.  O.  W.  could  have  guessed  something  of  the  direc¬ 
tion  and  the  extent  of  the  error,  when  he  unthinkingly  reached 
out  his  hand  over  the  cover  to  hand  the  experimenter  his  pencil 
— and  of  course  noticed  his  error.  He  announced  that  he  would 
try  not  to  heed  this,  and  at  the  end  of  the  long  series  of  sittings 
felt  that  it  had  not  influenced  him  in  the  least.  He  was  astonished 
to  find  that  he  had  not  been  hitting  in  the  same  place  all  the  time. 

A  distinct  illusion  that  developed  in  M.  O.  W.’s  case  is  strik¬ 
ing.  He  took  it  for  granted  that  when  he  was  seated  at  the  table 
he  was  sitting  “at  right  angles  to  it”,  with  the  three  buzzers  di¬ 
rectly  in  front  of  him.  Therefore  when  he  localized  a  buzzer,  es¬ 
pecially  the  middle  one,  he  thought  his  finger  was  striking  the  board 
at  the  back  at  a  right  angle.  As  a  matter  of  fact  the  buzzers  ap- 


t 


THE  DEVELOPMENT  OF  A  NEW  SPATIAL  CO-ORDINATION  33 


peared  over  20  cm.  to  his  right  and  hence  the  finger  struck  at  an 
angle  nearer  45  degrees  than  90  degrees.  But  to  him  all  the  time 
the  angle  was  a  right  angle,  and  the  tip  of  his  finger  seemed 
pressed  squarely  against  the  board.  The  illusion  was  made  clear 
when  at  the  end  of  the  series  he  made  a  few  trials  without  the 
glasses.  This  time  his  finger  actually  was  at  right  angles  to  the 
board  and  the  tip  against  it ;  but  he  reported  a  very  strong  feeling 
that  now  the  angle  was  acute,  and  that  it  was  with  the  side  of  the 
end  of  his  finger  that  he  seemed  to  be  touching  the  board !  The 
illusion  was  so  strong  and  persistent  that  he  could  not  get  rid 
of  it.  This  is  an  excellent  illustration  of  the  relativity  of  the 
tactual  local  sign  system. 

It  is  the  case  of  D.  S.  in  this  group  which  is  most  unequivocal. 
(See  curves  in  Fig.  III.)  Hers  was  the  most  rapid  adjustment, 
yet  she  felt  all  the  time  that  she  was  hitting  to  the  left  of  the 
buzzers !  “I  haven't  thought  about  what  the  glasses  were  doing 
each  day — or  at  all,”  she  said.  “They  merely  made  things  more 
hazy  .  .  .  Every  time  I  put  my  finger  in  place  I  felt  that  if  I 
moved  a  little  to  the  right  I’d  be  more  accurate.”  To  her  also  the 
three  buzzers  seemed  directly  in  front.  When  she  was  taking  a 
sitting  with  the  glasses  after  her  regular  sittings  were  over  and 
the  situation  finally  made  clear  to  her,  she  said,  “Seem  to  be 
reacting  as  usual.  Still  I  could  almost  swear  I  am  going  to  the 
left  of  the  buzzer  each  time,  although  I  know  from  conversation 
I  was  going  to  the  right.  .  .  The  kinaesthetic  clues,  though  I 
watch  for  them  now,  don’t  help  me.” 

2.  Effect  of  Position  of  Body,  Head,  and  Eyes 

The  results  of  the  second  group,  A-i-b,  show  clearly  that 
knowledge  of  the  nature  and  direction  of  the  distortion  is  not  an 
essential  condition  of  readjustment.  The  next  hypothesis  that 
seemed  most  fruitful  concerned  the  effect  on  the  localization  of 
the  buzzers  of  head  and  body  position. 

It  is  reasonable  to  suppose  in  the  first  place — and  casual  ob¬ 
servation  confirms  the  view1 — that  in  fixating  the  right  hand  buz¬ 
zers,  53  and  66,  the  head  of  the  subject  was  turned  relatively 
farther  to  the  right  than  was  the  body.  This  is  because  under  the 


34 


MARGARET  WOOSTER 


conditions  of  distortion  the  point  midway  between  the  two  end 
buzzers  appeared  to  be  about  20  cm.  to  the  right  of  the  main 
perpendicular  axis  of  the  body  of  the  subject,  considering  him 
as  facing  the  table  squarely.  Now  the  subjects  (in  view  of  the 
auditory  series  included)  were  all  told  to  move  the  head  and  body 
freely,  as  they  chose.  Bu  in  fixating  a  point  far  to  the  right 
the  head  would  naturally  be  turned  farther  than  the  body,  since 
we  are  accustomed  to  fixate  objects  with  relatively  little  body 
movement  as  compared  with  head  movement.  Now  the  arm 
and  hand  might  naturally  tend  to  assume  a  position  in  line  with 
the  central  body  position  rather  than  that  of  the  head,  for  the 
following  reason.  While  wearing  the  prismatic  glasses,  the  sub¬ 
ject,  in  fixating  the  buzzers  as  they  appear  to  him,  turns  his  head 
and  eyes  about  20  degrees  to  his  right.  But  the  buzzers  are  in 
the  center  of  his  field  of  vision,  and  as  he  reacts  to  them,  it  is 
with  the  same  “set”  that  he  would  have  were  they  directly  in 
front  of  him.  (Cf.  M.  O.  W.’s  illusion  of  position.)  Now  in  the 
course  of  his  normal  experience  reacting  “in  front”  has  come  to 
mean  always  reaching  out  more  or  less  at  right  angles  to  the 
body.  This  association  may  well  persist  in  the  abnormal  situation, 
so  that  if  the  head  is  turned  farther  to  the  right  than  the  body, 
the  subject  in  reaching  out  for  the  buzzers  “in  front  of  him” 
as  they  appear  to  be,  will  tend  to  reach  out  according  to  the 
old  habit  in  front  of  his  body.  This  might  well  explain  a  tendency 
to  depart  from  the  initial  localizations  far  to  the  right,  in  the 
direction  of  the  central  body  position.  We  might  explain  the 
gradual  nature  of  the  change  by  a  decrease  in  attention  to  the 
accuracy  of  the  localization  as  the  process  becomes  automatic. 

In  the  second  place  the  localizing  of  buzzer  53  involved  a 
reach  to  the  right  unnaturally  long  for  most  subjects,  who  always 
commented  on  the  length  of  the  reach.  When  an  unusual  reach 
in  any  direction  is  involved,  a  reach  accompanied  by  noticeable 
muscular  strain,  would  not  the  mere  influence  of  inertia  cause 
a  relaxation  in  the  strain  of  reaching  when,  as  in  this  experiment, 
there  is  no  practical  check  on  the  correctness  of  the  reaching 
movement?  And  might  not  the  tendency  connected  with  the  buz- 


THE  DEVELOPMENT  OF  A  NEW  SPATIAL  CO-ORDINATION  35 


zer  53  conceivably  influence  the  reaction  to  the  other  buzzers  in 
similar  degree? 

It  is  clearly  possible,  then,  that  the  readjustment  to  the  left 
may  be  caused  first  by  a  tendency  for  reaching  movements  to 
be  in  line  with  the  central  bodily  attitude  rather  than  that  of  the 
head;  and  second  by  a  tendency  to  react  in  the  direction  of  least 
muscular  exertion.  Considering  both  of  these  possible  sources  of 
influence,  might  we  not  expect  a  subject  under  normal  conditions 
of  vision,  to  show  a  progressive  “adjustment”  to  the  left  in 
seeking  to  localize  buzzers  placed  as  far  to  the  left  as  the 
buzzers  appeared  to  be  when  distorted  by  the  glasses? 

Conversely,  let  us  suppose  a  subject  wearing  the  prismatic 
glasses,  and  localizing  buzzers  placed  so  far  to  his  right  that 
the  muscular  strain  and  disparity  in  head  and  body  position 
would  be  to  the  right  in  localizing  the  buzzers  as  distorted,  in¬ 
stead  of  to  the  left.  Might  we  not  then  expect  to  find  such  a  subject 
showing  a  tendency  to  “readjust”  to  the  right  instead  of  to  the 
left,  so  that  our  curves  would  indicate  a  tendency  to  depart  from 
the  actual  position  of  the  object  instead  of  a  tendency  to  approach 
it? 


a.  Experiments  With  Undistorted  Vision. 

In  order  to  find  the  relation  of  body  position  to  readjustment 
on  the  basis  of  these  two'  converse  possibilities,  we  arranged  two 
groups  of  experiments.  In  the  first,  A-2-a,  we  aimed  to  keep  the 
conditions  exactly  as  in  A-i-a,  the  only  difference  being  that 
glasses  with  lenses  made  of  plain  window  glass  were  substituted 
for  the  prismatic  spectacles.  The  reach  to  the  right  was  about 
the  same  as  in  the  earlier  series  since  all  four  of  the  buzzers  were 
set  over  to  the  right  along  the  rod  about  18  cm.,  that  being  about 
the  average  amount  of  linear  distortion.  A  support  for  the  rod 
prevented  an  exact  shifting,  the  new  positions  being  at  35,  48, 
64,  and  74  along  the  scale  instead  of  at  53,  66,  79,  and  92  as 
formerly.  Instructions  given  the  subjects  were  exactly  the  same, 
nothing  being  said  about  might  be  expected  except  in  the  case  of 
one,  A.  M.,  who  was  given  the  suggestion  that  the  glasses  dis¬ 
torted  the  visual  field  and  that  she  might  be  expected  to  adjust 


36 


MARGARET  WOOSTER 


to  the  left.  Five  subjects  took  the  test — A.  M.,  A.  H.  M.,  G., 
L.  M.  J,  and  E.  S.  R. 

The  results  did  indeed  for  all  the  five  subjects  show  a  curve.  But 
the  curve  was  very  unlike  that  obtained  for  the  preceding  groups. 
It  showed  a  rise,  usually  within  the  first  three  or  four  sittings, 
of  between  one  and  four  cm.,  after  which  it  settled  down  into  a 
fluctuating  “straight”  line  which  rose  at  times  only  to  descend 
again  to  practically  the  original  level.  The  average  curves  for  all 
four  positions  for  io  days  are  indicated  in  Figure  X  by  the  wavy 
line.  It  will  be  remarked  at  once  that  the  curves  are  not  much 
lower  than  for  the  first  two  groups  in  which  the  glasses  were 
worn.  But  the  significant  thing  is  that  while  the  curves  for  the 
first  two  groups  keep  on  rising  until  half  way  up,  those  for  this 
group  continue  to  cling  close  to  the  lower  line. 

It  is  impossible  to  compare  the  groups  in  respect  to  remainders 
or  per  cents  of  readjustment,  for  in  the  group  under  consideration 
we  have  no  individual  linear  deviations  and  no  “normal”  re¬ 
actions  as  standards.  But  we  can  take  as  a  measure  the  difference 
in  centimeters  between  the  highest  point  reached  in  io  sittings 
for  each  buzzer,  and  the  average  of  the  five  initial  localizations 
for  that  buzzer.  Taking  the  averages  for  groups  A-i-a  and  A-2-a 
we  get  the  results  shown  in  Table  II.  (The  numbers  represent 
the  four  positions  of  the  buzzers,  from  right  to  left,  number  four 
being  at  92  for  group  A-i-a,  and  at  74  for  group  A-2-a.) 


TABLE  II 

Amount  of  Improvement  in  10  sittings 


Group 

Number  of  Subjects 

1 

2 

3 

4 

Av. 

A-i-a 

7 

7-9 

6.7 

6.4 

5-8 

6.7 

A-2-a 

5 

4-3 

3-3 

3-3 

3-3 

3-5 

It  is  seen  that  the  average  highest  amount  of  increase  over  the 
first  localizations  is  twice  as  much  for  the  group  wearing  the 
prismatic  glasses  as  for  the  present  group.  Only  three  of  the 
five  subjects  in  this  group,  unfortunately,  continued  the  sittings 
beyond  the  tenth.  Of  these  curves  of  G.  shows  an  increase  in 
amount  of  improvement  of  only  1.8  cm.  in  the  last  five  sittings. 


THE  DEVELOPMENT  OF  A  NEW  SPATIAL  CO-ORDINATION  37 


Subject  E.  S.  R.  continued  for  26  sittings  with  no  increase  over 
the  high  point  in  his  seventh  sitting,  but  a  slight  and  gradual  de¬ 
crease  which  brought  his  curves  down  at  the  end  to  within  an 
average  of  a  half  centimeter  of  his  record  for  the  first  sitting. 
(See  curve  Fig.  IV,  p.  38.) 

At  this  point  E.  S.  R.  was  started  in  the  standard  series, 
wearing  the  prismatic  glasses.  In  23  sittings  he  had  gained  8.1 
cm.,  an  improvement  of  41  per  cent  over  the  first  standard  sitting. 
Although  his  rate  of  improvement  is  slow,  it  seems  clear  that  it 
is  a  readjustment  to  the  new  visual  conditions.  In  Figure  IV,  p. 
38  the  unbroken  line -shows  E.S.R.’s  “progress”  in  the  undistorted 
series,  the  distance  from  the  lower  dotted  line  representing  aver¬ 
age  deviation  in  successive  day’s  sittings  from  the  actual  position 
of  the  buzzer.  Superimposed  upon  this  curve  is  the  broken  line 
showing  his  progress  while  wearing  the  glasses  (distorted  series). 
Here  the  distance  from  the  upper  dotted  line  represents  the  actual 
position  of  the  buzzer.  This  figure  points  clearly  to  an  essential 
difference  in  the  type  of  progress  without  and  with  glasses.  In 
the  former  case  there  is  wavering  with  no  true  upward  progress; 
in  the  latter  the  curve,  while  it  fluctuates,  keeps  on  steadily  rising. 

In  line  with  these  results,  though  less  conclusive,  are  those 
of  A.  H.  Her  curves  without  prismatic  glasses  do  not  for  15 
sittings  rise  beyond  the  highest  point  reached  in  the  first  10 
sittings  (an  improvement  of  3.8  cm.).  But  between  the  first  and 
second  sittings  with  prismatic  glasses  there  is  an  average  increase 
of  4  cm.,  pointing  plainly  to  the  operation  of  an  effective  incentive 
to  readjustment. 

It  must  be  confessed  that  we  have  too  few  subjects  in  this 
“undistorted  group”  to  justify  an  unqualified  conclusion  that 
without  the  prismatic  glasses  progress  does  not  continue.  More 
data  are  needed.  But  we  can  say  that  very  probably  the.  true 
situation  is  this :  The  difference  in  muscular  strain  caused  by 
the  unequal  reach  to  the  right,  or  the  natural  tendency  to  react 
with  reference  to  the  central  body  attitude,  or  both,  do  indeed 
result  in  a  tendency  to  “readjust”  to  the  left.  This  tendency, 
however,  is  very  slight,  and  effective  only  for  a  short  period.  It 
could  very  well  account  for  the  rapid  but  brief  initial  rise  which 


ct \LaX  positi o'tv  of  lovx.x'z.er  —  dl’i  stort  eciu  ser\es 


38 


MARGARET  WOOSTER 


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THE  DEVELOPMENT  OF  A  NEW  SPATIAL  CO-ORDINATION  39 


we  noted  as  characteristic  of  the  curves  for  the  first  two  groups; 
but  it  could  not  account  for  the  continued  and  steady  progress  of 
the  curves  which  indicate  a  per  cent  of  readjustment  as  high  as 
79.  It  would  have  been  possible  to  devise  an  extra  series  to  isolate 
the  factors  of  muscular  strain,  due  to  long  arm  reach,  and  of 
head-body  disparity;  but  owing  to  limited  time  this  was  not 
done.  The  two  factors  together  did  not  prove,  in  fact,  to  have 
much  influence,  as  will  be  brought  out  later. 

b.  Experiments  With  Distorted  Vision. 

In  the  second  group  of  experiments  to  test  the  effect  of  the 
bodily  attitude  and  muscular  strain  situations,  our  aim  was  to  see 
if  we  could  obtain  a  curve  in  the  opposite  direction,  or  at  least 
one  approximating  a  straight  line,  by  shifting  the  buzzers  far 
to  the  left  as  suggested,  so  that  the  localization  of  the  buzzers  as 
distorted  would  involve  an  unusual  reach  and  a  turning  of  the 
head  to  the  left.  Certainly  if  the  first  adjustment  were  independent 
of  the  prismatic  glasses,  such  an  adjustment  could  be  produced  in 
this  way  in  a  direction  contrary  to  that  which  theoretically  would 
take  place  to  “overcome”  the  prismatic  deviation. 

In  the  new  test,  A-2-b,  for  three  of  the  subjects  all  conditions 
were  exactly  as  in  A-i-b  (Experiments  without  knowledge),  ex¬ 
cept  that  the  three  buzzers  were  set  far  to  the  subject’s  left  in 
such  a  position  that  when  distorted,  the  one  farthest  to  the  right 
would  appear  to  be,  even  for  the  maximum  linear  deviation, 
slightly  to  the  left  of  the  normal  perpendicular  to  the  central 
body  axis,  while  the  localization  of  the  one  farthest  to  the  right 
would  involve  a  long  reach  accompanied  by  unusual  muscular 
strain.  The  positions  on  the  scale  for  the  three  buzzers  were  91, 
101,  and  1 17. 

In  Table  III,  p.  41,  is  a  summary  of  the  numerical  results  for 
this  group.  Fig.  V,  p.  40  shows  typical  curves,  those  of  E.  H. 
E.  and  R. 

Four  subjects  took  this  test,  all  continuing  for  at  least  10 
sittings.  Not  one  of  them  showed  a  tendency  to  readjust  to  the 
right.  Three  on  the  contrary  showed  a  very  marked  readjustment 
to  the  left,  working  thus  against  an  increasing  sense  of  muscular 


MARGARET  WOOSTER 


40 


Fig.  V.  Standard  series.  Distorted. 


THE  DEVELOPMENT  OF  A  NEW  SPATIAL  CO-ORDINATION  41 

strain,  which  they  mentioned.  The  one  who  did  not  readjust  re¬ 
mained  more  or  less  on  a  level  for  a  few  days,  then  fell  to  a 
level  only  very  slightly  higher  than  for  the  first  sitting. 

Of  the  three  subjects  who  showed  marked  improvement,  none 
were  aware  of  the  extent  of  the  deviation  and  were  even  uncertain 
of  its  direction  at  times.  E.  H.  E.,  on  seeing  her  results,  felt 
greatly  surprised  that  she  had  been  making  a  progressive  change ; 
and  that  the  “feeling  in  her  arms”  did  not  inform  her  of  this. 
She  thought  she  had  been  hitting  in  the  same  positions  all  the 
time. 

H.  A.  C.  was  very  familiar  with  all  the  conditions  of  the  ex¬ 
periment,  and  a  highly  trained  observer.  At  the  fifth  sitting  he 
reported  that  all  the  time  he  felt  as  if  he  were  going  too  far  to 
the  left,  and  when  his  finger  got  there,  he  felt  that  if  he  moved 
it  a  little  to  the  right,  it  would  be  more  correct.  At  the  ninth 
sitting  he  said,  “Don’t  know  whether  Eve  improved  or  not — 
if  I  were  going  to  guess,  would  say  probably  I  hadn’t — largely 
guess  work.” 

In  Table  III  is  a  summary  of  the  results  for  the  four  subjects 
for  a  10  day  period. 


TABLE  III 

Readjustment  with  Buzzers  at  the  Left,  Distorted  Vision. 


Subject 

Average 

Remainder 

Per  Cent 
Readjustment 

Average 
Initial  L.D. 

P.  R. 

5-0 

68 

15-5 

F.  0.  D. 

2.1 

85 

10.0 

E.  H.  E. 

.8 

99 

10.2 

H.  A.  C. 

10.0 

22 

9.8 

Average 

4-5 

68 

12.3 

On  first  glance  at  these  figures  it  would  seem  that  the  read¬ 
justment  even  on  the  average  was  so  much  more  rapid  than  that 
in  the  standard  series  as  to  require  the  supposition  either  of 
another  causative  factor  or  of  an  unusual  coincidence  in  the 
matter  of  individual  variability.  But  consideration  of  the  effect 
of  the  changed  position  of  the  buzzers  explains  this  apparent 
discrepancy.  The  amount  of  linear  deviation  varies  regularly 
with  the  size  of  the  angle  included  between  the  line  of  fixation 


42 


MARGARET  WOOSTER 


and  the  line  of  projection  (the  scale),  according  to  the  formula 
c  sin  B 

b  —  - -  where  b  is  the  linear  deviation  (L.  D.)  and  B  the 

sin  C 

angle  of  deviation  of  the  prisms.  Now  if  the  other  angle,  A, 
formed  by  the  line  of  fixation  for  a  buzzer  and  the  scale  is  small, 
then  the  L.  D.  is  correspondingly  smaller.  Now  all  the  A’s  in  this 
situation  are  less  than  right  angles,  while  in  the  other  groups  all 
were  greater.  This  means  that  the  L.  D.  will  be  much  smaller, 
and  in  fact  we  do  find  the  average  L.  D.  here,  12.3  cm.,  to  be 
less  than  two  thirds  of  the  average  L.  D.  for  the  first  series  A- 
i-a  and  A-i-b,  which  is  19  cm. 

Now  with  a  smaller  L.  D.  the  same  absolute  amount  of  read¬ 
justment  would  not  only  correspond  to  a  disproportionately 
larger  per  cent  of  total  readjustment,  but  the  remainder  would 
also1  be  smaller.  For  example,  suppose  the  absolute  amount  re¬ 
covered  by  two  subjects  in  each  group  to  be  5  cm.,  and  the  L.  D. 
to  be  20  cm.  Now  for  the  subject  in  A-i-a  this  would  represent 
25  per  cent  of  readjustment  and  a  remainder  of  15  cm.,  while 
for  a  subject  recovering  the  same  distance  in  group  A-2-b,  the 
per  cent  of  readjustment  would  be  50  and  the  remainder  only 
5  cm.  Hence  we  see  that  the  two  sets  of  results  are  not  directly 
comparable,  and  may  assume  that  in  reality  the  average  L.  D.  of 
these  subjects  would  be  about  the  same  as  in  the  first  group,  were 
conditions  the  same;  and  that  the  amount  of  readjustment  would 
not  be  greatly  different. 

Now  under  the  conditions  of  this  series  with  distorted  vision 
the  head  must  be  either  in  line  with  the  body  or  turned  farther 
to  the  left.  Hence  the  fact  that  marked  readjustment  to  the  left 
nevertheless  occurs  proves  conclusively  that  although  the  head- 
body  discrepancy  may  have  been,  and  presumably  was,  slightly 
effective  in  causing  the  original  readjustment,  a  much  more  ef¬ 
fective  cause  must  have  been  at  the  basis  of  the  readjustment  for 
most  subjects.  The  same  statement  holds  for  the  hypothesis  that 
the  original  readjustment  may  have  been  due  to  a  gradual  re¬ 
laxation  in  attention  to  localization  with  a  consequent  following 
of  the  direction  of  least  bodily  effort,  for  in  this  case  readjust¬ 
ment  took  place  in  the  direction  of  increasing  bodily  strain. 


THE  DEVELOPMENT  OF  A  NEW  SPATIAL  CO-ORDINATION  43 


It  becomes  necessary  again  to  search  for  other  possible  factors. 
We  have  a  gradual  change  in  method  of  localizing,  marked  and 
steadily  increasing  for  most  subjects,  without  any  known  basis, 
sensory  or  ideational,  for  such  a  change.  Now  every  reaction  must 
have  a  conditioning  stimulus,  immediate  or  remote.  What  is  the 
stimulus  here? 

After  much  pondering  a  possible  solution  of  this  problem  came 
to  mind,  suggested  by  the  line  of  reasoning  followed  in  discussing 
the  head-body  position.  Briefly  the  theory  is  as  follows.  The 
position  of  the  eyes  in  the  head  is  such  that  they  are  turned  to  the 
right  of  the  head  axis,  just  as  the  head  is  to  the  right  with 
reference  to  the  central  axis  of  the  body.  It  is  the  habitual  tend¬ 
ency  to  react  to  the  front  as  determined  by  head  position  rather 
than  eye  position  which  conditions  the  tendency  to  readjust  to 
the  left.  The  other  factors  of  head-body  position  and  of  tend¬ 
ency  to  equalize  strain  may  enter  in  as  subordinate  influences, 
but  the  main  incentive  to  readjustment  is  the  eye-head  situation. 

Let  us  see  what  the  exact  implications  of  this  hypothesis  are. 
It  may  be  said  that  there  are  for  the  individual  three  distinct 
meanings  of  the  word  “front” — one  with  reference  to  the  central 
axis  of  the  body,  one  with  reference  to  the  head  axis,  and  one  with 
reference  to  the  line  of  vision  when  the  fovea  is  stimulated  by  the 
fixated  object.  Now  it  is  reasonable  to  suppose  the  foveal  front 
to  be  less  dominating  in  the  habitual  reaction  systems  of  the  in¬ 
dividual  than  the  head  front.  In  the  first  place  the  eye  is  much 
more  active  and  varied  in  the  direction  of  its  fixation  than  the 
head.  In  the  second  place  it  is  necessary  to  recognize  the  exist¬ 
ence  in  this  experiment  of  two  different  sensory  aspects,  visual 
and  kinaesthetic,  of  the  concept  front,  whereas  normally  the 
bodily  reactions  to  the  kinaesthetic  and  the  visual  situations  are 
objectively  the  same.  That  is,  the  subject  now  sees  the  buzzer 
in  front  to  be  in  one  place,  but  with  his  head  and  body  he  feels 
that  “front”  is  in  another  direction,  farther  to  the  left.  If  the 
subject  wearing  the  glasses  saw  his  head  and  body  at  the  same 
time  he  saw  the  buzzer,  it  is  possible  that  this  old  kinaesthetic 
set  would  be  harmonized  with  the  new  visual  situation  and  the 
localizations  would  be  consistently  in  one  place.  But  the  glasses 


44 


MARGARET  WOOSTER 


are  so  constructed,  and  the  conditions  of  the  experiment  are  such, 
that  the  subject  does  not  see  any  part  of  his  head  or  body.  Hence 
it  is  natural  that  the  old  or  normal  kinaesthetic  reaction  tend¬ 
encies  should  be  very  strong  when  the  subject  is  working  under 
the  injunction  to  reach  out  “in  front”,  and  that  there  should  be 
a  marked  tendency  to  point  in  the  direction  of  the  head-axis 
rather  than  the  eye-axis  which  is  for  the  time  being  farther  to  the 
right. 

At  first  when  the  subject  might  be  expected  to  give  particular 
attention  to  the  localization  of  the  novel  visual  object,  he  would 
respond  to  it  by  precise  movements  in  harmony  with  the  new 
visual  situation.  But  since  the  attention  of  the  subject  gradually 
lessens  and  the  process  becomes  automatic,  it  is  quite  natural 
that  he  should  by  degrees  fall  back  into  the  more  usual  habit 
of  reacting  in  harmony  with  the  normal  “feel”  of  the  head.  This 
would  explain  the  gradual  nature  of  the  readjustment  to  the  left. 

The  superiority  of  this  explanation  over  the  other  hypotheses 
advanced  lies  in  the  fact  that  unlike  them  it  works  in  the  series 
with  distorted  vision  just  described.  It  is  not  hard  to  show  that 
no  matter  what  the  direction  of  the  line  of  vision,  the  eye  will 
still  be  turned  in  its  socket  farther  to  the  right  than  in  normal 
fixation.  In  normal  foveal  fixation  of  an  object  the  line  of  vision 
and  the  head-axis  coincide.  When  the  prism  is  placed  before  the 
eye  of  the  subject,  the  object  is  deflected  to  the  right,  and  in  order 
to  adjust  properly  to  it  the  head  is  turned  to  the  right  together 
with  the  attached  prism.  But  this  turning  of  the  prism  again  alters 
the  angle  of  incidence  of  the  ray  of  light  from  the  object,  with 
the  result  that  it  is  refracted  to  the  periphery  of  the  retina.  Hence 
and  in  order  to  obtain  clear  foveal  fixation,  the  eye  must  turn 
still  farther  in  the  socket.  Otherwise  the  object  would  be  seen 
in  peripheral  vision,  an  unnatural  situation  for  an  object  attended 
to.  The  amount  of  sequential  turning  of  the  eye  is  sufficient  to 
make  the  eye-head  discrepancy  clearly  apparent  to  the  observer 
as  the  subject  is  in  the  act  of  localizing  a  buzzer. 

This  optical  situation  can  be  stated  in  a  definite  mathematical 
formula  by  the  physicist,  but  it  is  sufficient  for  our  purposes  to 
recognize  the  mere  fact  that  for  every  turn  of  the  head  there 


THE  DEVELOPMENT  OF  A  NEW  SPATIAL  CO-ORDINATION  45 

will  be  a  sequential  turning  of  the  eye  still  farther  to  the  right, 
at  an  angle  of  noticeable  extent,  though  less  than  the  angle 
between  the  head-axis  and  the  main  body-axis.  Taking  into  ac¬ 
count  the  existence  of  this  discrepancy,  and  the  highly  complex 
and  delicate  way  in  which  the  performance  of  any  act  is  in¬ 
fluenced  by  the  total  sensory  situation  at  the  moment,  it  is  easy 
to  understand  the  readjustment  to  the  left  as  a  perfectly  natural 
adaptation  to  the  changed  sensory  situation  induced  by  the  prisms. 
It  is  clear  now  why  no  marked  readjustment  occurs  when  the 
prisms  are  not  worn. 

The  progressive  character  of  the  readjustment  can  be  explained 
on  this  hypothesis  in  two  ways.  In  the  first  place  the  subject 
might  at  first  concentrate  his  attention  on  the  visual  stimulus 
and  the  correctness  of  his  reaction  to  it,  and  hence  react  with 
reference  to  the  “foveal  front.”  Later,  though  the  foveal  fixation 
is  still  maintained,  he  might  naturally  relax  his  vigilance  and 
fall  comfortably  into  the  more  habitual  manner  of  reacting  with 
reference  to  the  “head  front”. 

Or,  in  the  second  place,  he  might  continue  consistently  to  re¬ 
act  with  respect  to  the  foveal  axis,  but  that  axis  itself  might 
change,  in,  let  us  say,  the  following  way.  At  first  the  subject,  anx¬ 
ious  to  localize  the  object  correctly,  takes  pains  to  get  a  clear  foveal 
fixation.  But  this  involves  some  muscular  strain  since  the  eye  is 
turned  farther  in  the  socket  than  normally.  And  he  can  attend 
to  the  object  visually  through  peripheral  as  well  as  foveal  fixation. 
What  is  more  natural  than  that,  as  the  process  of  reacting  be¬ 
comes  increasingly  automatic,  the  eye  should  relax  its  tension  and 
gradually  assume  a  compromise  position  nearer  its  normal  posi¬ 
tion  in  the  head ;  or  even  continue  until  it  has  reached  the  normal 
position?  This  means  that  the  eye-axis  would  slowly  approach 
the  head-axis,  and  finally,  in  some  cases,  coincide  with  it.  As- 
uming  that  in  this  case  the  reaction  of  the  subject  is  always 
with  reference  to  the  foveal  front,  the  above  assumption  would 
account  nicely  for  the  progressive  character  of  the  readjustment 
to  the  left.  Individual  differences  in  readjustment  would  be  due 
to  physiological  differences  in  susceptibility  to  muscular  strain. 

It  seems  probable  that  readjustment  due  to  this  prism-induced 


46 


MARGARET  WOOSTER 


eye-head  discrepancy  may  be  effected  in  both  these  ways,  some 
subjects  reacting  in  one  way,  some  in  another.  That  the  general 
fact  of  the  eye-head  discrepancy  is  very  significant  for  the  pro¬ 
cess  of  readjustment  appears  highly  probable.  The  chief  merit 
of  the  hypothesis  is  that  it  will  hold  for  the  case  in  which  read¬ 
justment  to  the  left  took  place  even  in  the  direction  of  increasing 
bodily  strain  and  in  the  face  of  a  slight  turning  of  the  head  to 
the  left  as  compared  with  the  body.  For  no  matter  what  the 
direction  of  the  object  with  reference  to  the  body,  we  know  that 
the  eyes  will  always  be  turned  in  their  sockets  to  the  right  of  their 
normal  position. 

There  are,  however,  some  difficulties  which  indicate  that  this 
hypothesis  is  very  likely  only  a  partial  explanation,  and  not  suf¬ 
ficient  to  explain  all  the  facts  we  have  discovered  in  the  course 
of  our  experiments.  How,  for  instance,  on  this  basis,  can  we  ac¬ 
count  for  the  fact  that  in  the  case  of  R.  D.  in  the  Auditory 
Series  readjustment  occurred  rapidly  and  surely,  and  then  halted 
and  remained  on  a  level  for  ten  days  at  exactly  the  point  of  ob¬ 
jectively  correct  localization?  R.  D’s  localizations  here  were, 
moreover,  far  more  accurate  reactions  than  she  had  made  to 
sound  alone.  According  to  the  present  theory  why  should  the 
readjustment  stop  at  any  particular  point,  much  less  at  this  point? 
Unfortunately  in  none  of  the  other  cases  in  the  first  and  second 
series  where  complete  or  nearly  complete  readjustment  seemed 
to  occur,  were  the  sittings  continued  long  enough  to  see  if  the 
process  would  go  on  indefinitely. 

This  hypothesis  did  not  occur  to  the  writer  until  after  the 
conclusion  of  the  experimental  work  for  the  investigation,  when 
it  was  too  late  to  check  it  up  experimentally.  In  a  later  sup¬ 
plementary  investigation,  however,  the  writer  hopes  to  carry  out 
the  experimentation  necessary  to  clear  up  the  matter. 

It  may  be  said  parenthetically  at  this  point  that  in  the  later 
series  in  which  complete  readjustment  occurred,  due  to  known 
sensory  clues,  the  readjustment  should  on  this  theory  go  on, 
though  at  a  slower  rate,  to  a  point  some  distance  to  the  left  of 
the  actual  position  of  the  objects.  There  is  no  reason  to  assume 
that  this  would  not  have  occurred,  yet  here  again  positive  evi- 


THE  DEVELOPMENT  OF  A  NEW  SPATIAL  CO-ORDINATION  47 

dence  is  needed,  since  the  sittings  were  stopped  when  the  actual 
position  of  the  buzzers  was  reached. 

VISUAL  LOCALIZATION  OF  SOUNDING  OBJECTS 
1.  First  Group,  Using  Electric  Buzzer 

The  second  main  series  of  experiments  was  designed  to  test 
the  efficacy  of  sound  as  a  factor  in  the  formation  of  the  new 
visual  coordination.  For  the  first  group  of  experiments  in  this 
series  one  of  the  electric  buzzers  was  used  as  the  object  to  be 
localized.  In  this  case  it  was  sounded  at  each  trial.  One  buzzer  was 
used  instead  of  four  as  in  the  preceding  series,  and  shifted  be¬ 
tween  trials  to  different  ones  of  the  four  positions  53,  66,  79, 
and  92,  according  to  a  predetermined  order.  The  object  of  using 
the  one  buzzer  instead  of  four  was  first,  to  keep  the  quality  of 
the  sound  as  nearly  constant  as  possible.  It  was  found  practically 
impossible  to  get  four  buzzers  of  the  kind  employed  that  were 
of  the  same  pitch  and  timbre,  or  to  equalize  those  we  had.  The 
second  object  was  to  make  possible  an  easy  identification  of  the 
sounding  buzzer.  If  but  one  of  four  was  sounding,  it  would  be 
a  hard  task  for  a  subject  wearing  the  prisms  to  tell  at  once  which 
one  it  was. 

Before  starting  the  main  series  of  trials  with  distorted  vision, 
a  preliminary  series  was  given  to  test  the  accuracy  of  the  sub¬ 
ject  in  normal  auditory  localization  of  the  buzzer  in  the  four 
positions.  The  subject,  after  being  instructed  how  to  reach  out  for 
the  buzzer,  was  blindfolded  and  seated  at  the  apparatus.  At  the 
signal  “Ready,”  followed  by  the  sound,  he  was  to  decide  carefully 
at  about  what  point  along  the  rod  the  buzzer  was,  moving  his 
head  and  body  freely  as  desired,  and  taking  all  the  time  needed, 
the  sound  meanwhile  continuing.  When  he  had  decided,  he  was  to 
reach  out  and  make  the  localization.  When  he  touched  the  board 
the  sound  stopped.  In  order  that  the  subject  might  not  know  or 
guess  from  what  position  the  sound  was  to  be  expected,  (1) 
he  was  not  told  that  only  four  positions  were  used;  (2)  the  trials 
were  given  in  regular  order  but  the  order  was  frequently  changed; 
and  (3)  the  buzzer  was  moved  noiselessly  between  trials,  con- 


48 


MARGARET  WOOSTER 


versation  going  on  in  the  meanwhile.  The  interval  between  trials 
was  one  minute.  Fifty  trials  were  taken  for  each  of  the  four 
different  positions  of  the  buzzer,  from  20  to  30  trials  being 
given  in  a  day’s  sitting. 

When  the  preliminary  series  had  been  completed  the  subject 
began  the  series  with  distorted  vision,  with  procedure  exactly 
as  in  the  first  main  series,  A-i,  except  that  the  one  buzzer,  shifted 
between  trials,  was  used  instead  of  four,  and  that  the  experi¬ 
menter  gave  the  signal  for  reacting  by  sounding  the  buzzer  in¬ 
stead  of  by  placing  her  finger  on  it.  The  typewritten  instructions 
were  exactly  as  in  the  standard  series,  A-i,  except  for  the  change 
in  describing  the  signal  for  reaction.  Nothing  was  said  about 
localizing  the  sound.  The  object  was  thus  to  see  if  the  subject, 
while  localizing  the  visual  object,  would  be  influenced  by  its 
sound,  coming  from  a  position  to  the  left. 

The  results  of  this  series  as  first  given  to  four  subjects  seemed 
strongly  to  indicate  that  sound  is  efficacious  as  a  factor  in  the 
formation  of  the  new  visual  coordination.  The  progress  of  these 
subjects  was  noticeably  more  rapid  than  that  of  those  in  Series 
A,  for  in  the  10  day  period  their  average  remainder  was  less  by 
24  per  cent  and  the  average  remainder  for  all  the  sittings,  or 
“total  remainder,”  less  by  41  per  cent.  While  none  of  the  sub¬ 
jects  in  the  standard  group  showed  a  higher  total  per  cent  of 
readjustment  than  75,  and  all  but  one  fell  below  60,  only  one 
subject  of  the  four  in  the  sound  group  (B-i)  fell  below  60, 
and  one  showed  100  per  cent  readjustment  in  12  days.  The 
sittings  in  both  groups  were  continued  until  the  apparent  limit 
of  improvement  had  been  reached.  Since  on  the  average  the 
individuals  in  the  sound  group  had  one  less  sitting  than  the  stand¬ 
ard  group  their  smaller  total  remainder  could  not  have  been 
due  to  more  practice. 

In  the  course  of  these  experiments  with  sound,  certain  of  the 
subjects — and  it  happens  the  slowest  ones — reported  that  they 
did  not  associate  the  sound  with  the  buzzer  at  all.  It  seemed  to 
come  from  another  place,  and  so  they  got  to  thinking  of  it 
merely  as  a  signal  for  reacting.  One  even  persisted  in  believing, 
despite  the  assurances  of  the  experimenter,  that  it  was  another 


THE  DEVELOPMENT  OF  A  NEW  SPATIAL  CO-ORDINATION  49 


buzzer,  behind  the  apparatus,  that  was  sounding.  This  suggested 
the  desirability  of  experiments  to  see  if  the  fact  of  knowledge 
or  lack  of  knowledge  that  sight  and  sound  came  from  the  same 
object,  would  make  any  difference  in  the  rate  of  readjustment. 

2.  Second  Group,  Using  Electric  Bell 

For  this  group  it  was  necessary  to  use  a  sounding  object  in 
which  the  vibration  at  the  time  of  sounding  should  be  clearly 
visible  to  the  subject.  A  “midget”  electric  door  bell  3.5  cm.  in 
diameter,  mounted  and  made  adjustable  like  the  buzzers,  and  very 
similar  to  them  in  size  and  appearance,  was  used.  The  little 
hammer,  painted  a  bright  red,  vibrated  conspicuously  when  the 
bell  was  sounded.  For  the  group  in  which  the  vibration  was  to 
be  invisible,  a  small  brass  “wing”  was  made  which  could  be 
quickly  screwed  to  the  upper  part  of  the  bell,  and  which  effectively 
prevented  the  subject  from  seeing  the  vibrating  hammer  from 
any  angle. 

For  these  experiments  with  the  bell  the  instructions  to  the 
subject  were  essentially  as  in  B-i,  except  that  for  the  group  in 
which  the  vibration  was  visible  the  attention  of  the  subject  was 
called  to  the  energetic  tattoo  which  the  little  red  hammer  kept  up 
when  the  bell  was  sounded. 

Three  subjects  were  used  for  the  first  group  (B-2-a)  in  which 
the  vibration  was  visible,  and  three  for  the  second  group  (B-2-b) 
in  which  the  vibration  was  invisible.  The  sittings  were  continued 
until  the  limit  of  improvement  had  apparently  been  reached — for 
this  group,  for  about  30  sittings. 

The  results  of  the  experiments  with  the  bell  were  inconclusive. 
There  was  no  appreciable  difference  in  either  rate  or  amount  of 
readjustment.  In  fact  the  individuals  in  group  b,  who  did  not 
have  the  objective  assurance  that  the  sight  and  sound  belonged 
together,  showed  on  the  average  a  slightly  higher  rate  and  amount 
of  improvement  than  those  in  group  a.  Their  average  10  day 
remainder  was  only  8  cm.,  while  the  corresponding  remainder  for 
the  three  in  group  a  was  9.5  cm.  The  results  of  both  groups 
were  indeed  strikingly  like  those  for  B-i. 

After  the  experiments  with  the  bell  (B-2)  two  more  subjects 


50 


MARGARET  WOOSTER 


were  tested  out  for  io  days  in  the  B-i  series  with  the  buzzers. 
Both  of  these  subjects  (R.  and  H.  E.  C.)  showed  a  very  small 
amount  of  readjustment,  their  remainders  for  the  io-day  period 
being  14  cm.  and  12  cm.  respectively,  and  the  per  cents  of  read¬ 
justment  only  27  and  32.  This  brought  the  average  in  group 
B-i  so  low  that  on  comparing  the  two  groups  as  a  whole,  we  find 
a  far  less  significant  difference  between  the  standard  and  the 
sound  groups  than  had  appeared  before.  The  superiority  of  the 
sound  group  over  the  standard  group  was  by  these  two  additions 
reduced  in  regard  to  the  10-day  remainder  from  24  per  cent  to 
14  per  cent  and  in  regard  to  the  10-day  readjustment  from  26 
per  cent  to  18.5  per  cent.  It  is  a  question  whether  the  small  per 
cent  of  improvement  of  these  two  subjects  does  not  indicate 
merely  a  lack  of  general  susceptibility  to  readjustment,  an  in¬ 
dividual  peculiarity  that  certainly  exists.  Unfortunately  their 
sittings  did  not  extend  beyond  the  tenth,  and  so  there  is  no  way 
of  telling  whether,  like  O.  B.  B.  in  the  standard  group,  they  might 
have  shown  a  spurt  of  progress  later  on. 

The  individual  and  group  results  for  all  3  of  the  B  groups  are 
given  in  Table  IV.  The  results  for  B-2-a  (vibration  visible)  and 
B-2-b  (vibration  invisible)  are  combined  after  B-2-b,  since  there 
is  no  esesntial  difference  between  them. 

The  figures  for  auditory  accuracy  reveal  a  good  deal  of  in¬ 
dividual  consistency  considering  the  relative  crudeness  of  the 
arrangements.  While  there  are  wide  limits  of  variability  among 
the  different  members  of  the  group,  the  average  mean  deviation 
for  the  group  for  all  four  positions  being  6.3  cm.,  the  individual 
variability  is  less.  The  highest  mean  deviation  for  any  individual 
is  5.1  cm.,  while  the  lowest  is  3.6  cm.  The  distance  between  the 
four  different  positions  of  the  buzzers,  it  will  be  recalled,  is  13 
cm.  All  of  the  subjects,  therefore,  were  able  under  normal  con¬ 
ditions  not  only  to  distinguish  by  sound  alone  the  four  different 
positions,  but  within  this  range  of  13  cm.  quite  accurately  to 
localize  the  particular  source  of  the  sound. 

Under  the  conditions  of  distorted  vision  the  great  majority  of 
the  subjects  were  conscious  as  soon  as  the  sittings  started  of  the 
approximate  actual  position  of  the  sound.  In  general  they  re- 


THE  DEVELOPMENT  OF  A  NEW  SPATIAL  CO-ORDINATION 


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52 


MARGARET  WOOSTER 


ported  that  it  seemed  at  each  trial  to  be  to  the  left  of  the  buzzer, 
estimating  the  distance  to  be  from  6  to  30  cm.  from  its  apparent 
position.  Subject  C.  S.,  in  group  B-2,  is  the  only  one  who  thought 
for  a  while  that  the  sound  was  to  the  right,  but  she  soon  dis¬ 
covered  her  error.1  Subject  M.  M.  (group  B-2)  is  the  only  one 
in  the  series  (including  15  subjects)  who  did  not  at  any  point 
in  her  sittings  localize  the  sound  as  to  the  left  of  the  apparent 
position  of  the  object. 

In  considering  the  remainders  and  per  cents  of  readjustment  in 
the  sound  series  it  will  be  convenient  to  deal  with  the  group  re¬ 
sults.  In  Table  V,  p.  58,  is  a  summary  of  the  results  by  groups 
of  A-i,  the  standard  group  of  seven  subjects,  using  four  buzzers; 
B-i,  the  first  sound  group  of  six  subjects,  using  one  buzzer;  and 
B-2,  the  second  sound  group  of  6  subjects,  using  the  bell.  The 


TABLE  V 

Summary  of  Group  Results  for  Series  A  and  B 


Group 

No. 
Subj . 

Av. 

L.D. 

R. 

10-da. 

R. 

Total 

Sit¬ 

tings 

Percent 
Readj. 
10  da. 

Percent 

Readj. 

Total 

A-i-a 

7 

19. 1 

12.5 

8.7 

21 

35 

56 

A-i-b 

4 

17.7 

10.6 

9i 

22 

38 

(47) 

B-i 

6 

18.3 

10.8 

7-7 

22 

4i-5 

(73) 

Improvement  of 

B-i  over  A-i 

13-6% 

u.5% 

I 

18.5 

(30.3)* 

B-2 

6 

19.6 

8.0 

2.8 

29.5 

64.0 

87.5 

A(i-a  and  i-b) 

11 

18.4 

II-5 

8.9 

22.0 

36.5 

(47)* 

B(i  and 2) 

12 

19 

9.4 

5-3 

25-7 

527 

80 

Improvement  of 

B  over  A 

17.2% 

40% 

44% 

(70%)* 

*For  four  subjects  only. 


1  Toward  the  beginning  of  her  sittings,  C.  S.  even  reported  at  one  time 
that  she  “saw  the  experimenter  in  one  place  and  heard  her  voice  in  another” 
(to  the  left).  It  is  of  interest  here  to  note  that  M.  O.  W.  (in  series  A-2) 
first  discovered  the  direction  of  the  prismatic  deviation  through  noticing 
a  similar  discrepancy  between  the  sound  of  the  experimenter’s  voice,  and 
her  position  as  reported  by  sight. 


)ev  i  a-tiO'tL  m  c  erit  i,  Trt.  ale,  rs 


THE  DEVELOPMENT  OF  A  NEW  SPATIAL  CO-ORDINATION  53 


Fig.  VI.  Auditory  Series. 


combined  results  of  B-i  and  B-2  and  the  combined  results  of 
A- 1 -a  and  A-i-b  (without  knowledge)  are  also  given. 

The  group  curves  for  A-i  are  shown  compared  with  the  group 
curves  for  B-i  in  Fig.  X.  Specimen  curves  for  B  are  given  in 
Fig.  VI. 

From  an  inspection  of  these  tables  and  curves  it  will  be  seen 
that  there  are  some  indications  that  sound  is  an  influential  factor 
in  the  process  of  readjustment.  Comparing  group  B-i  with  the 
standard  group  in  which  the  buzzers  were  not  sounding,  we 
find  for  the  io  day  period  a  remainder  less  by  13.6  per  cent  than 
that  for  the  standard  group,  and  a  per  cent  of  improvement  18.5 
per  cent  greater.  If  we  combine  the  results  for  A-i  (with  knowl- 


54 


MARGARET  WOOSTER 


edge)  and  A-2  (without  knowledge),  and  compare  them  with  the 
combined  results  for  B-i  (using  buzzer)  and  B-2  (using  bell), 
we  find  a  still  greater  difference.  The  io  day  remainder  for  the 
sound  group  is  now  less  than  that  for  the  standard  group  by 
17.2  per  cent.  The  amount  of  readjustment  for  10  days  is  greater 
by  44  per  cent. 

Now  while  these  differences,  considering  the  large  amount  of 
individual  variation,  by  no  means  justify  even  the  positive  con¬ 
clusion  that  the  sound  had  any  influence  at  all  in  forming  the 
new  coordination,  they  certainly  do  indicate  the  probability  that 
sound  may  be  a  factor. 

An  indication  that  sound  as  employed  in  our  experiments  may 
be  a  factor  in  the  formation  of  the  new  coordination,  is  the 
fact  that  some  subjects  report  that  they  feel  a  positive  “pull” 
in  the  direction  of  the  sound,  or  in  other  words,  toward  the  actual 
position  of  the  buzzer.  A.  C.  W.,  for  instance,  in  his  later  sittings, 
felt  such  a  tendency.  Localizing  the  buzzer  as  it  appeared  to  be, 
he  described  as  like  “pushing  up  stream.” 

This  consideration  is  offset  by  the  fact  that  a  majority  of  the 
subjects  not  only  felt  no  “pull”,  but  paid  very  little  if  any  atten¬ 
tion  to  the  sound.  The  report  was  common  that  the  sound  served 
merely  as  a  signal  for  reacting,  or  as  a  sort  of  “orchestral  ac¬ 
companiment”.  Several,  though  they  always  localized  the  sound 
— as  to  the  left — felt  that  it  made  no  difference  in  their  re¬ 
actions.  The  most  striking  negative  evidence  occurs  in  the  case 
of  M.  M.  (group  B-2 )  who,  though  she  made  steady  progress 
and  finally  made  a  readjustment  of  88  per  cent,  reported  that  she 
was  not  at  all  conscious  that  the  sound  was  to  one  side  of  the 
buzzer,  and  did  not  even  know  until  the  very  last  the  direction  of 
the  distortion.  (See  M.  M’s  curves  in  Fig.  VI.). 

One  subject,  K.  J.,  localized  the  sound  as  to  the  left,  and 
mentioned  noticing  it  frequently.  It  was  impossible  to  get  him 
to  adopt  a  naive  attitude  toward  the  experiment,  and  it  was 
quite  evident  that  he  was  determined  to  resist  the  suggestion  that 
occurred  to  him  that  the  sound  was  expected  to  influence  him, 
as  these  typical  remarks  indicate:  “Of  course  you  realize  the 
sound  doesn’t  make  a  particle  of  difference,”  and  “Why  are  you 


THE  DEVELOPMENT  OF  A  NEW  SPATIAL  CO-ORDINATION  55 


sounding  the  buzzer  at  all?”  In  K.  J’s  curves  given  in  Fig.  VI 
we  see  an  actual  progressive  regression  from  the  actual  posi¬ 
tion  of  the  buzzer,  a  unique  situation  among  the  72  subjects.  It 
seems  plausible  that  the  regression  may  be  due  to  the  unconscious 
influence  on  the  localizations  of  the  stubborn  determination  not 
to  be  influenced  by  the  sound. 

As  a  matter  of  fact,  suggestive  as  the  above  reports  of  sub¬ 
jects  are  as  to  the  factors  which  did  or  did  not  influence  them, 
they  have  not  a  particle  of  value  as  scientific  evidence.  A  sub¬ 
ject  might  be  sure,  as  M.  R.  G.  was  in  series  A,  that  he  was  reach¬ 
ing  to  the  same  point  each  time,  and  yet  actually  be  steadily  ad¬ 
vancing  to  the  left,  influenced  by  factors  of  whose  existence  he 
was  entirely  unaware.  Similarly,  subjects  who  reported  that  they 
paid  no  attention  to  the  sound  may  nevertheless  have  been  in¬ 
fluenced  by  it,  just  as  people  may  respond  to  irritating  stimuli 
during  sleep,  or  waken  if  an  accustomed  stimulus  ceases. 

An  attempt  to  see  whether  the  sound  might  cause  additional  re¬ 
adjustment  after  a  subject  had  reached  the  limit  of  improvement 
in  the  standard  series,  proved  fruitless  as  far  as  gaining  definite 
evidence  was  concerned.  This  is  what  might  have  been  expected, 
for  as  has  been  pointed  out,  it  had  been  found  that  some  subjects 
in  the  standard  series  whose  curves  remained  on  a  level  for 
some  time,  showed  unexpectedly  new  progress  in  readjustment. 
The  fact,  however,  that  four  out  of  the  five  subjects  tested  in 
this  way  did  show  at  least  a  slight  improvement  immediately 
after  the  introduction  of  sound,  is  worthy  of  attention.  The  * 
subject  whose  curves  exhibited  no  change  whatever  on  the  in¬ 
troduction  of  sound  was  M.  W.,  the  writer,  who  was,  it  happens, 
the  only  one  in  the  standard  series  who  showed  no  progress  in 
that  series.  The  improvement  shown  by  M.  R.  G.  and  D.  S.  is  only 
what  might  have  been  expected  had  no  change  in  conditions  been 
made. 

In  series  A-2,  however,  the  increase  in  readjustment  of  M.  O. 
W.  and  of  M.  Me  F.,  after  the  introduction  of  sound,  seems 
possibly  significant.  The  curves  of  M.  O.  W.,  which  after  28 
sittings  had  remained  on  a  level  for  six  sittings,  showed  an  average 
rise  of  2.5  cm.  in  the  first  sitting  in  which  sound  was  given.  In 


56 


MARGARET  WOOSTER 


the  next  16  sittings  the  per  cent  of  readjustment  increased  from 
37  to  45.  The  curves  of  M.  McF.,  which  after  35  sittings  had 
remained  at  a  level  for  10  days,  showed  a  slight  rise  during  the 
three  days  after  the  introduction  of  sound  (an  average  rise  of 
3.4  cm.).  There  was  then  a  slump  due  to  a  fortnight’s  vacation 
and  a  10  days’  absence  on  account  of  illness,  after  which  the 
curves  showed  a  steady  rise  for  nine  days  and  a  total  advance 
over  the  record  for  the  sittings  without  sound,  of  34  per  cent 
in  amount  of  readjustment,  while  the  remainder  decreased  from 
8.6  cm.  to  4.2  cm. 

Such  facts  as  the  above  may  well  make  us  hesitate  before 
concluding  that  sound  has  no  efficacy  in  our  experiments.  Another 
aspect  of  the  situation  is  this:  Inasmuch  as  subjects  in  the 
standard  series  have  shown  a  great  deal  of  individual  difference 
in  susceptibility  to  whatever  factors  make  for  improvement,  may 
it  not  be  that  some  subjects  are  influenced  by  the  sound  and 
others  not?  May  not  the  unusually  rapid  progress  of  R.  D.  and 
of  C.  S.  be  correlated  with  their  interest  in  the  sound  and  its 
location,  while  others  are  not  similarly  influenced?  Here  of  course 
the  influence  of  sound,  if  there  be  any,  may  be  said  to  consist  mere¬ 
ly  in  the  emphasis  of  the  direction  and  amount  of  distortion.  The 
situation  is  so  complex,  and  there  are  so  many  possible  factors 
that  it  is  in  fact  impossible  to  conclude  from  the  slight  evidence 
we  have,  that  sound  is  efficacious  in  these  two  cases. 

Even  if  sound  does  have  some  influence  in  the  process  of  read¬ 
justment,  it  is  clear  that  in  our  experiment,  that  influence  is  slight, 
and  not  susceptible  of  quantitative  measurement.  As  an  illustra¬ 
tion  let  us  take  the  case  of  R.  D.,  who  showed  a  readjustment  of 
100  per  cent  in  12  sittings.  From  an  inspection  of  her  curves  in 
Fig.  VI,  it  is  seen  that  for  10  days  after  attaining  an  approx¬ 
imately  correct  localization  of  the  buzzers,  the  curves  fluctuate 
about  the  same  general  level.  Now  if  it  were  the  sound  of  the 
buzzers  that  was  determining  her  localizations,  the  average  for 
these  10  sittings  should  roughly  coincide  with  her  average  normal 
auditory  localization.  But  as  a  matter  of  fact  R.  D.  localized  the 
sound  of  the  buzzer  normally  over  6  cm.  to  the  right  of  its  actual 
position.  (See  Table  IV.)  While  the  sound  may  have  influ- 


THE  DEVELOPMENT  OF  A  NEW  SPATIAL  CO-ORDINATION  5 7 


enced  her,  then,  it  was  not  by  virtue  of  exerting  a  definitely  meas¬ 
urable  “pull”  toward  a  certain  particular  position. 

In  this  connection  it  is  pertinent  to  note  the  fact  that  while 
the  exact  localization  of  the  sound  is  unstable  and  shifts  within 
rather  wide  limits,  it  is  for  the  great  majority  of  the  subjects  at 
first  a  relatively  independent  matter.  At  the  begining  of  the  sit¬ 
tings  the  sound  is  clearly  assigned  to  a  position  definitely  to  the 
left  of  the  object  as  seen.  It  is  only  as  the  sittings  progressed  and 
readjustment  took  place  that  the  discrepancy  between  sound  and 
sight  was  reported  as  becoming  less.  Many  of  the  subjects  re¬ 
ported  that  at  the  close  of  the  sittings  sight  and  sound  seemed 
to  be  at  last  together,  and  the  finger  to  “feel”  in  the  right  place 
too. 

Now  while  the  sound  comes  finally  in  the  process  of  readjust¬ 
ment  to  be  “pulled  over”  to  the  sight,  the  subjects  were  not  so 
suggestible  on  this  point  as  some  of  Stratton’s  observations  might 
lead  one  to  expect.  The  localization  of  the  sound  in  our  experi¬ 
ments  is  a  relatively  independent  matter,  changing  only  gradually 
in  response  to  the  demands  of  the  practical  situation. 

The  following  conclusions  may  be  drawn  from  the  experiments 
on  sound  in  series  B  : 

1.  There  is  evidence  that  sound  may  have  a  slight  influence 
in  the  formation  of  the  new  spatial  coordination  developed  under 
the  conditions  of  our  experiment,  especially  for  some  subjects. 

2.  If  sound  does  have  an  influence,  this  influence  operates 
in  general  without  awareness  of  that  fact  on  the  part  of  the  subr 
ject. 

3.  The  fact  of  perceiving  or  not  perceiving  the  direct  con¬ 
nection  of  the  sound  with  the  vibrating  visual  object,  has  under 
the  conditions  of  our  experiment  no  influence  on  the  rate  or 
amount  of  readjustment. 

4.  The  conditions  of  our  experiment  are  not  definite  enough, 
especially  in  the  matter  of  directions  to  subjects,  to  insure  a 
fair  test,  of  the  efficacy  of  sound  as  a  factor  in  the  formation  of 
the  new  coordination.  There  is  need  for  a  better  experimental 
technique  in  this  matter. 


58 


MARGARET  WOOSTER 


LOCALIZATION  WITH  TOUCH 

The  next  series,  C,  was  designed  to  determine  the  influence 
of  contact  with  the  buzzer  upon  the  rate  and  amount  of  read¬ 
justment  to  the  changed  visual  conditions.  For  this  series  one 
buzzer  only  was  used.  This  was  shifted  from  one  of  the  four 
positions  to  another  according  to  a  regular  order.  The  slit  at  the 
back  of  the  cover  was  widened  just  enough  to  permit  of  lower¬ 
ing  the  buzzer  half  way  down  through  it.  The  subject,  on  making 
a  correct  localization,  would  thus  touch  the  lower  half  of  the 
buzzer  without  seeing  his  finger.  The  contact  with  the  relatively 
cool  smooth  buzzer  was  distinctly  different  in  quality  from  the 
usual  contact  with  the  wood  forming  the  back  of  the  apparatus. 

Contact  was  the  sole  means  of  determining  the  actual  position 
of  the  buzzer.  It  was  not  sounded.  The  localizing  finger  could  not 
be  seen  by  the  subject  even  though  the  slit  was  wider  than  in  the 
preceding  series,  because  the  narrow  wood  strip  one  cm.  in  thick¬ 
ness  (which  formed  the  front  of  the  frame  supporting  the  slid¬ 
ing  cover)  acted  as  a  sort  of  screen.  As  in  the  preceding  series, 
in  order  that  the  subject  might  not  find  out  the  extent  of  his 
error  by  visual  means,  through  seeing  the  experimenter’s  move¬ 
ments  in  getting  the  records,  the  black  curtain  was  drawn  after 
each  localization. 

i.  Passive  Touch,  as  the  Result  of  Chance  Success 

In  the  first  group  of  experiments  with  touch  the  subject 
localized  the  buzzer  exactly  as  in  the  standard  series,  reacting 
to  its  apparent  position,  but  with  the  knowledge  that  when  he 
made  an  objectively  correct  localization  he  would  touch  the 
buzzer.  In  other  words  he  knew  each  time  he  reached  out  that  he 
was  missing  the  buzzer.  There  would  be  no  actual  contact  with 
the  buzzer,  then,  unless  by  accident  or  until  almost  complete  read¬ 
justment  should  occur. 

In  the  case  of  the  three  subjects  in  this  group,  it  was  found 
that  the  knowledge  each  time  that  the  localization  was  wrong, 
had  apparently  no  effect  upon  the  rate  of  readjustment.  The 
results  were  in  all  respects  like  those  of  the  standard  series.  (See 


THE  DEVELOPMENT  OF  A  NEW  SPATIAL  CO-ORDINATION  59 

Table  VI.)  Complete  readjustment  occurred  in  the  case  of  only  one 
subject.  In  his  case  it  was  plainly  due  to  an  accidental  direct  con- 

TABLE  VI 


Groups  C- 1  ( Active  Touch)  and  C-2  ( Passive  Touch) 


No.  of 

Visual  Acc. 

Av.L.D. 

Rem. 

Rem.  Per  Cent 

Subjects 

Sit- 

53 

66 

79 

92 

1st 

10  da. 

T  o'tal 

Readj . 

tings 

trial 

10  da. 

C-i 

* 

T.  L.  W. 

18 

53-5 

66.5 

80.6 

937 

13. 

+  1.4 

+  1.4 

90. 

M.  K. 

10 

53-9 

65.8 

78.3 

91.0 

21 

18 

14 

R.  J.  B. 

20 

54-i 

66.8 

78.6 

91.2 

22.3 

19-3 

19-3 

13 

C-2 

F.  D. 

11 

534 

67.0 

79-9 

92.4 

24.9 

•5 

#  # 

98 

D.  B. 

13 

55-0 

67.6 

81.0 

94.0 

234 

34 

2.0 

85 

M.  B. 

10 

53-0 

66.0 

79-7 

91.9 

19.1 

.23 

•  • 

99 

G.  B. 

12 

52.8 

66.8 

79-3 

93-0 

20.4 

1.0 

•55 

95 

F. 

10 

53-9 

66.6 

80.0 

92.2 

21.2 

.96 

•  • 

95 

Average 

11 

1.02 

944 

R.  D. 

9 

53-2 

66.0 

78.3 

91.7 

84 

10.2 

•  • 

45 

tact  with  the  buzzer.  The  other  two  did  not  approach  sufficiently 
close  to  the  buzzer  to  admit  of  the  occurrence  of  a  chance  touch. 
One  of  these  subjects,  R.  J.  B.,  was  one  of  the  few  of  the  entire 
number  of  72  subjects  who,  like  M.  W.  in  the  standard  series, 
made  no  significant  progress  at  all,  although  she  had  20  sittings. 
The  results  for  this  group,  then,  were  indeed  essentially  like  those 
of  A- 1,  and  served  only  still  further  to  confirm  the  conclusions 
drawn  from  them. 

The  results  of  one  subject  of  the  three,  however,  furnish  a  bit 
of  interesting  evidence.  T.  L.  W.  accidentally  touched  buzzer  four, 
at  position  79,  at  the  first  localization  in  his  fifth  sitting.  As  a 
result  all  the  following  localizations  were  much  nearer  the  actual 
position  of  the  buzzer,  although  T.  L.  W.  was  not  conscious  of 
the  change.  (See  T.  L.  W.’s  curves  in  Fig.  VII.)  The  curves 
for  all  the  positions,  which  had  for  the  four  sittings  shown  no 
advance  at  all,  rose  after  this  one  contact  experience  an  average 
of  6.  1  cm.  in  the  one  sitting!  Moreover,  the  influence  of  the 
contact  was  strongest  for  the  particular  position  where  it  occurred, 
(buzzer  3)  and  least  for  one  farthest  away  (buzzer  1).  At  the  end 
of  the  10th  sitting  there  was  complete  recovery  for  buzzer  3,  but 


6o 


MARGARET  WOOSTER 


for  buzzer  i  recovery  was  not  complete  until  the  18th  sitting.  All 
this  regular  and  rapid  readjustment  took  place  while  T.  L.  W.  was 
reacting  automatically  to  the  position  of  the  buzzer  as  it  appeared 
to  him! 

The  case  of  T.  L.  W.  shows  in  a  striking  way  the  marked 
efficacy  of  direct  contact  as  a  factor  in  readjustment.  But  it  is 
plain  that  with  the  instructions  used  in  this  group,  direct  con¬ 
tact  would  occur  only  rarely,  in  the  case  of  a  few  subjects. 

The  results  of  the  group  as  a  whole  show  only  that  the  ob¬ 
jective  knowledge  of  error,  when  contact  was  not  felt,  had  no 
effect  in  hastening  readjustment.  This  is  significantly  in  line  with 
the  results  of  Series  A-i-b  (without  knowledge). 

2.  Active  Touch,  as  a  Check  at  Each  Localization 

In  the  next  series  the  aim  was  to  test  the  influence  of  the  factor 
of  active  touch  as  a  check  at  each  localization.  For  this  group  the 
subject  reacted,  as  in  all  the  series,  to  the  apparent  position  of 
the  buzzer.  But  after  each  localization  made  in  that  manner,  he 
checked  the  accuracy  of  his  localization  by  actual  contact,  accord¬ 
ing  to  the  following  directions: 

“When  you  have  touched  the  board,  keep  your  finger  in  position 
while  the  screen  is  adjusted  and  until  the  experimenter  says  ‘All 
right/  Then,  not  taking  the  finger  from  the  board,  move  it  along 
until  you  touch  the  side  of  the  buzzer.  Then  put  your  finger  tip 
squarely  on  the  black  line  as  it  extends  beneath  the  cover.  Now  sit 
back  in  the  chair  and  wait  for  the  next  ‘Ready’  signal.” 

After  the  first  localization  the  subject  would  move  his  finger 
uncertainly  along  the  board,  as  often  in  the  wrong  direction  as 
the  right  one,  and  would  usually  not  touch  the  buzzer  until  after 
some  retracing.  After  this  there  would  be,  after  each  localization, 
one  natural  movement  in  the  right  direction,  leading  to  the  contact 
experience.  Of  course  with  this  revised  procedure  we  do  not 
have  as  the  additional  factor  a  simple  contact  value,  but  one  com¬ 
plicated  with  kinaesthetic  stimuli.  In  other  words  we  have  active 
or  exploratory,  rather  than  passive  touch. 

In  dealing  with  the  results  of  series  C,  D,  and  E  we  must  keep 
in  mind  the  fact  that  in  these  groups,  as  pointed  out  in  the  dis- 


THE  DEVELOPMENT  OF  A  NEW  SPATIAL  CO-ORDINATION  61 


cussion  on  pp.  18  and  19,  the  per  cent  of  readjustment  is  a  less 
reliable  measure  of  improvement  than  in  series  A  and  B.  This, 
it  will  be  remembered,  is  due  to  the  fact  that  in  these  later  series 
the  readjustment  occurs  so  rapidly  as  to  make  extremely  am¬ 
biguous  the  figures  expressing  initial  linear  deviation. 

An  illustration  from  series  C-2  of  the  fact  that  readjustment 
takes  place  within  the  first  four  trials  is  afforded  by  the  results 
of  D.  B.  From  Table  VI,  p.  64,  it  is  seen  that  her  initial  devi¬ 
ations  for  positions  53,  66,  79,  and  92  are  24,  23.1,  27,  and 
19.5  cm.,  respectively.  Now  according  to  the  linear  deviation 
calculable  from  trigonometric  formula  on  the  basis  of  the  angle 
of  the  prisms  and  the  angle  at  each  of  these  positions,1  the  great¬ 
est  deviation  should  be  at  53,  and  the  amounts  should  be  succes¬ 
sively  less  for  the  other  buzzers.  The  fact  that  instead  the  order 
of  greatest  deviation  is  79,  53,  66,  and  92,  is  easily  accounted  for 
by  the  fact  that  the  trials  were  given  in  just  that  order.  Thus 
for  each  successive  trial  we  have  a  decrease  in  deviation,  due  to 
the  tendency  to  readjustment — a  decrease  so  marked  as  to  obscure 
the  common  objective  difference  in  linear  deviations  due  to  angle 
and  position. 

The  individual  results  for  series  C  are  given  in  Table  VI,  and 
specimen  curves  in  Fig.  VII.  In  the  table  a  plus  sign  before  a 
remainder  indicates  that  it  represents  “over-correction”,  or  local¬ 
ization  to  the  left  of  the  actual  position  of  the  buzzer.  The  curves 
for  four  of  the  five  subjects  in  group  C-2  exhibit  a  uniform 
and  gradual,  but  very  rapid  readjustment.  On  the  average  the 
remainder  of  these  subjects  at  the  end  of  the  10th  sitting  is  only 
1.02  cm.,  and  the  per  cent  of  readjustment  is  94.4.  One  subject, 
R.  Dixon,  is  a  notable  exception.  Apparently  touch  is  not  effective 
in  her  case  at  all,  for  her  very  lowest  remainder  is  10.2  cm., 
and  after  that  point  (at  the  sixth  sitting)  her  curves  recede  again 
until  at  the  ninth  sitting  they  are  nearly  as  low  as  at  the  beginning. 

These  results  are  decisive  evidence  that  touch  is  a  powerful 
factor  in  the  formation  of  the  new  habit  of  spatial  reaction.  That 
one  subject  was  apparently  not  influenced  by  this  factor,  only  in¬ 
dicates  again  the  existence  of  marked  individual  differences  in 


62 


MARGARET  WOOSTER 


Nu.Wber  o[  silU 

Fig.  VII.  Tactual  Series, 
c  sin  B 

1  b  — - .  See  p.  42. 

sin  C 

the  matter  of  adjustment  to  spatial  relations.  The  gradual  slope 
of  the  curves,  the  striking  correspondence  for  each  subject  of 
the  curves  for  the  four  different  positions,  and  the  general  sim¬ 
ilarity  of  the  curves  of  the  five  subjects  who  did  readjust,  all 


THE  DEVELOPMENT  OF  A  NEW  SPATIAL  CO-ORDINATION  63 


point  to  the  operation  of  a  consistently  powerful  stimulus  to  read¬ 
justment. 

The  fact  that  the  readjustment  did  not  occur  on  a  conscious 
level  needs  to  be  emphasized  here.  At  each  trial  the  subject  reached 
out  naturally  and  automatically  toward  the  buzzer  as  it  appeared 
to  him.  There  was,  after  each  localization,  the  knowledge  that  the 
actual  object  had  been  missed,  and  the  awareness  through  previous 
tactual-kinaesthetic  experience  of  its  approximate  location.  But 
since  there  was  no  conscious  attempt  to  correct,  the  “re-harmon¬ 
ization”  evidently  took  place  in  response  to  a  need  for  a  practically 
effective  response,  of  which  the  subject  himself  was  not  clearly 
aware. 

LOCALIZATION  WITH  VISUAL  PERCEPTION  OF 
AMOUNT  OF  DISTORTION 

The  aim  of  series  D  was  to  determine  the  relative  influence  of 
sight  of  the  localizing  finger  after  the  response,  in  the  formation 
of  the  new  spatial  coordination.  For  this  series  the  slit  at  the  back 
of  the  cover  was  made  wide  enough  to  permit  the  introduction 
of  the  finger  tip  when  a  localization  was  made,  in  such  a  way 
that  the  tip  only  of  his  finger  was  visible  to  the  subject.  At 
the  same  time  the  buzzers  were  raised  to  such  a  height  that 
the  finger  tip,  when  appearing  just  beneath  the  black  line,  did 
not  come  in  contact  with  the  buzzer.  All  four  buzzers  were 
used.  Instructions  and  general  procedure  were  exactly  as  in  the 
standard  series.  Thus  by  having  the  subject  react  to  the  apparent 
visual  position  of  the  buzzer,  we  were  able  to  test  the  effect  of 
visual  perception  of  the  amount  and  direction  of  error. 

Ten  subjects  took  part  in  this  series.  The  results  are  given  in 
Table  VII,  p.  67,  and  Fig.  VIII.  The  results  of  E.  B.,  M.  L.  P., 
P.  and  P.  I.,  while  given  in  the  table,  are  not  included  in  the 
general  averages  for  the  group.  This  is  because  they  had  less 
than  10  sittings  and  did  not  quite  reach  complete  readjustment. 
In  this  table,  as  in  Table  VI,  a  plus  sign  before  a  remainder 
indicates  an  excess  of  localization  to  the  left. 

It  was  perhaps  more  difficult  in  this  group  to  maintain  a  per- 


64 


MARGARET  WOOSTER 


XLA 


fectly  naive  and  uncritical  manner  of  response,  with  no  conscious 
effort  to  correct,  than  in  any  other  series.  But  there  were  more 
subjects,  and  moie  highly  trained  subjects,  in  this  group  than 
in  any  other  group.  They  all  reported  that  the  process  of  read¬ 
justment  was  pui  ely  effortless  and  they  were  uniformly  surprised 
when  the  distance  from  the  buzzer  first  began  to  decrease.  That 


THE  DEVELOPMENT  OF  A  NEW  SPATIAL  CO-ORDINATION  65 

the  process  was  spontaneous  and  automatic  is  indicated  by  the 
strikingly  gradual  slopes  of  the  curves  and  their  uniformity  for 
the  four  different  positions. 

The  curves  of  all  10  of  the  subjects  in  this  group  show  a 
very  rapid  readjustment,  amounting  in  10  sittings  to  an  average 
per  cent  of  readjustment  of  97,  with  a  remainder  of  only  .4  cm. 
This  shows  that  in  our  experiment,  vision  and  touch  seem  to  be 
almost  equally  powerful  factors  in  effecting  a  readjustment  to 
the  new  spatial  conditions.  The  curves  for  the  groups  (C  and  D) 
in  Fig.  X  exhibit  about  the  same  general  height  and  slope. 

A  study  of  both  the  curves  and  tables,  however,  reveals  sig¬ 
nificant  differences.  In  the  first  place  the  group  curves  seem  to 
indicate  that  the  rate  of  readjustment  is  more  rapid  for  series 
D  than  for  series  C.  The  curves  for  the  sight  series,  D,  are 
consistently  higher  on  the  average  than  those  for  the  touch  series, 
C.  Especially  striking  is  the  difference  for  the  first  two  sittings. 
On  first  thought  this  would  seem  to  indicate  a  more  rapid  initial 
readjustment  for  sight  than  for  touch.  The  numerical  results  in 
Table  IX,  p.  73,  however,  suggest  that  this  may  not  be  really  the 
case,  and  that  the  average  amount  of  deviation  is  so  much  less 
in  the  case  of  sight,  not  because  there  was  a  good  deal  more 
progress  within  the  first  sitting,  but  because  the  average  initial 
deviation  for  the  group  was  less  by  4.5  cm. 

But  why  is  the  average  initial  deviation  so  much  less  than  in 
the  case  of  the  sight  series?  There  are  two  possible  reasons.  First, 
it  may  be  due  to  mere  individual  variability  and  the  lack  of  a 
sufficient  number  of  cases  to  strike  a  typical  average.  There  are 
only  ten  subjects  in  Group  D  and  seven  in  Group  C.  Second,  it 
may  be  due  to  so  rapid  a  readjustment  in  the  case  of  the  sight 
series  that  the  average  deviation  for  the  four  buzzers  combined 
may  be  significantly  less  than  the  deviation  for  the  first  buzzer 
localized  in  the  sitting,  which  was  in  this  group  buzzer  92. 

Now  as  a  matter  of  fact  the  second  explanation  proves  on 
analysis  of  the  results  to  be  the  true  one.  While  the  average 
deviation  for  all  four  buzzers  is  17.6  cm.  for  the  sight  series,  the 
deviation  for  buzzer  92  is  21.3  cm.  for  the  group,  a  difference 


66 


MARGARET  WOOSTER 


of  3.7  cm.  Had  the  first  buzzer  to  be  localized  by  the  group  been 
53  or  66,  this  deviation  would  have  been  still  greater,  owing  to 
the  fact  that  the  standard  objective  deviation  for  buzzer  92  is 
the  least  of  the  four  buzzers.  The  average  initial  deviation  for 
the  other  three  buzzers  is  markedly  less  than  for  buzzer  92,  be¬ 
cause  the  process  of  readjustment  set  under  way  by  the  first 
localization  of  buzzer  92  is  already  proceeding  rapidly. 

Taking  these  facts  into  consideration  it  is  clear  that  the  average 
deviation  for  series  D,  which  is  calculated  on  the  basis  of  the 
average  of  the  initial  trials  only  for  each  position,  is  smaller 
than  that  for  series  C  for  the  reason  that  there  is  indeed  a  very 
rapid  readjustment  within  the  first  four  localizations  in  the  first 
sitting.  Individual  variability  might  account  for  a  small  amount 
of  difference  in  the  average  initial  localizations  for  the  two  groups, 
but  it  could  not  possibly  in  itself  account  for  the  striking  differ¬ 
ence  we  actually  find. 

The  second  significant  difference  between  the  results  for  the 
sight  and  the  touch  series  is  found  in  the  fact  that  not  only 
is  the  rate  of  readjustment  for  the  former  greater,  but  the  ab¬ 
solute  amount  of  readjustment  effected  within  the  given  10  day 
period  is  greater.  The  average  remainder  for  the  visual  group 
is  only  .4  cm.,  as  contrasted  with  1.02  cm.  for  the  tactual  group. 
(Table  IX.)  In  the  visual  group  four  out  of  the  seven  subjects 
who  took  10  sittings  showed  a  complete  readjustment,  while  not 
one  of  the  seven  subjects  in  the  tactual  group  effected  a  complete 
readjustment.  Another  indication  that  the  influence  toward  read¬ 
justment  afforded  by  the  sight  of  the  discrepancy  was  more 
strongly  operative  than  the  tactual  factor,  is  the  circumstance 
that  in  the  visual  group  five  out  of  seven  subjects  show  a  small 
average  “over  correction"  (.15cm.)  while  no  individual  in  the 
tactual  group  showed  an  average  “over  correction”  for  the  four 
positions.  It  is  as  if,  having  felt  a  strong  impetus  toward  read¬ 
justment,  the  subjects  in  the  visual  group  were  carried  a  little 
way  past  the  goal  by  the  mere  force  of  inertia. 

We  had  the  opportunity  to  find  out  whether  sight  was  a  more 
powerful  factor  than  touch  in  the  case  of  one  individual,  owing 
to  the  fact  that  after  a  long  series  of  sittings  with  touch  (19) 


THE  DEVELOPMENT  OF  A  NEW  SPATIAL  CO-ORDINATION  67 


she  showed  absolutely  no  further  improvement.  The  factor  of 
sight  was  then  substituted  for  that  of  touch  with  the  result  that 
an  immediate  improvement  set  in,  and  after  13  sittings  the  sub¬ 
ject  (M.  W.,  the  writer)  had  made  a  complete  readjustment. 

A  comparative  study  of  the  results  for  series  C  and  D,  then, 
indicates  that  the  factor  of  sight  as  used  in  our  experiments  is 
more  efficacious  in  the  formation  of  the  new  coordination  than 
the  factor  of  touch. 


TABLE  VII 

Visual  Perception  of  Amount  of  Distortion 


Sub¬ 

jects 

No.  of 
Sit¬ 
tings 

53 

Visual  Acc. 
66  79 

92 

Av.L.D. 

1st 

trial 

Av.Rem.  Total 

10  Per  Cent 

days  Readjust. 

J. 

L. 

B. 

1 7 

53-3 

66.0 

78.9 

92.2 

20.4 

14 

93 

P. 

J. 

R. 

10 

53-8 

66.1 

78.7 

91.6 

16.0 

2.3 

86 

G. 

10 

53-0 

66.3 

79.0 

92.0 

20.0 

.2 

100 

A. 

D. 

U. 

12 

52.7 

66.5 

98.8 

9i-3 

15.2 

.2 

99 

D. 

H 

.  B. 

6 

53-6 

66.2 

79-3 

91.8 

14.5 

.15 

101 

F. 

A. 

K. 

11 

52.7 

66.3 

79- 

91.2 

17-3 

.1 

100. 1 

F. 

R. 

8 

52.5 

66.9 

78.8 

9i-5 

19.8 

.1 

100 

Average 

10.6 

17.6 

4 

97 

E. 

B. 

7 

534 

64.6 

78.1 

91.9 

18.7 

•5 

97 

M. 

L. 

P. 

6 

53-5 

65.0 

78.2 

93-5 

16.2 

4 

97 

P. 

I. 

7 

53-i 

65.2 

78.6 

92.3 

134 

1. 1 

92 

LOCALIZATION  WITH  TACTUAL-KINAESTHETIC 

CLUES  FROM  LEFT  ARM 

Perhaps  one  of  the  strongest  habitual  simple  space  codrdi- 
nations  employed  in  daily  life  is  the  coordination  between  right 
and  left  hand  and  arm  movements,  so  necessary  for  grasping  and 
handling  objects.  Were  some  form  of  this  coordination  broken 
up  by  the  wearing  of  the  prismatic  glasses,  it  would  seem  that 
there  would  be  an  unusually  strong  tendency  to  re-form  the 
coordination  under  the  changed  visual  conditions.  It  was  the  aim 
of  series  E  to  see  what  is  the  relative  strength  of  this  tactual- 
kinaesthetic  influence  toward  readjustment  as  compared  with  the 
other  factors  investigated. 

The  procedure  was  as  follows.  The  subject  was  seated  at  the 
apparatus  in  the  usual  position,  wearing  the  glasses.  While  his 
eyes  were  closed  his  left  arm  was  extended  out  over  the  cover  by 


68 


MARGARET  WOOSTER 


the  experimenter,  and  he  was  directed  to  bend  the  left  index 
finger  so  that  it  would  extend  downward  at  the  back  of  the 
apparatus  through  the  slit,  which  had  been  sufficiently  widened 
for  this  purpose.  When  his  finger  was  in  position  the  subject  was 
permitted  to  open  his  eyes.  He  was  then  directed  to  localize  his 
left  index  finger  as  in  the  normal  series,  by  a  direct  movement 
of  the  right  index  finger  to  the  part  of  the  left  finger  extending 
beneath  the  cover.  He  was,  as  in  the  other  series,  to  localize  the 
finger  as  it  was  visually  perceived,  disregarding  the  fact  of  dis¬ 
tortion.  The  experiment  thus  tested  the  influence  upon  localization 
of  clues  as  to  the  correct  position  of  the  finger  derived  through 
the  tactual  and  kinaesthetic  senses. 

The  slit  was  so  wide  in  this  series  that  in  order  to  prevent 
sight  of  the  localizing  finger  by  the  subject  it  was  necessary  to 
provide  a  movable  cardboard  strip  to  cover  the  movements  of 
the  finger.  In  the  middle  of  this  strip,  which  is  56  cm.  long  and 
8  cm.  wide,  is  an  aperture  shaped  like  a  half  moon  through 
which  the  left  finger  of  the  subject  was  extended.  At  each  trial 
this  opening  was  set  at  the  desired  position,  53,  66,  79,  or  92, 
as  the  case  might  be.  The  same  order  and  number  of  trials  and 
the  same  length  of  interval  were  maintained  as  in  the  other  series. 

With  this  manner  of  procedure  the  subject  was  kept  just  as 
much  in  ignorance  of  the  direction  and  amount  of  the  distortion 
as  in  the  standard  series.  The  only  difference  was  that  in  this  series 
tactual-kinaesthetic  sensations  from  the  left  arm  afforded  clues  to 
the  actual  position  of  the  object.  Had  the  subject  been  permitted 
himself  to  extend  his  left  arm  over  the  cover  and  his  finger  down 
through  the  aperture,  he  would  have  gained  not  only  knowledge  of 
the  nature  of  the  distortion  but  practice  in  overcoming  it.  It  was 
for  this  reason  that  the  experimenter  put  the  arm  of  the  subject 
in  place  herself,  and  was  very  careful  that  the  subject  should 
withdraw  it  while  his  eyes  were  closed  and  the  curtain  still  in 
place  in  front  of  the  line  of  localization. 

Six  subjects  served  in  series  E,  for  10  days  each.  Results  are 
given  in  Table  VIII,  p.  71  and  Fig.  IX  p.  69.  The  most  striking 
feature  of  the  data  is  the  fact  that  for  all  of  the  subjects  the 


THE  DEVELOPMENT  OF  A  NEW  SPATIAL  CO-ORDINATION  69 


XTTHL 


initial  linear  deviations  are  very  much  lower  than  in  any  of  the 
other  series.  The  average  linear  deviation  for  this  group  is  only 
9.5  cm.,  while  the  lowest  average  for  the  four  other  series,  that 
of  series  D,  is  17.6  cm.  The  average  even  for  the  first  position 
localized,  92,  or  buzzer  4,  is  only  10.3  cm.  This  fact  can  apparently 
mean  only  one  thing,  viz.,  that  the  tendency  to  effect  a  practical 
coordination  of  the  movements  of  the  two  hands  is  so  strong  that 
it  is  impossible  with  our  glasses  to  break  it  up,  although  the  sub- 


70 


MARGARET  WOOSTER 


jects  acted  in  innocent  and  even  ignorant  good  faith  in  trying 
accurately  to  localize  the  left  finger  as  it  visually  appeared  to 
them.  In  other  words,  “readjustment”  to  the  changed  visual  con¬ 
ditions  is  on  the  average  more  than  50  per  cent  effective  prior 
to  the  first  localization.  Moreover,  since  the  subjects  reported  that 
they  were  unaware  of  the  direction  of  the  distortion,  this  “read¬ 
justment”  was  unconscious  on  their  part  and  occurred  solely  on 
the  basis  of  the  retention  of  habitual  kinaesthetic  attitudes. 

In  the  tactual-kinaesthetic  series,  it  is  to  be  kept  in  mind  that  the 
influence  of  the  sensory  incentive  to  readjustment  was  operative 
before  the  first  localization.  In  the  auditory  series  a  similar 
situation  prevailed,  since  the  sound  afforded  a  clue  as  to  the 
actual  position  of  the  buzzer  before  the  first  trial  was  made.  In 
the  sound  series,  however,  the  influence  of  such  a  condition  was 
not  apparent,  while  in  the  tactual-kinaesthetic  series  it  was  very 
marked.  In  no  other  series  could  the  clues  be  perceived  before 
actual  localizing  movements  began. 

A  second  striking  feature  of  the  results  peculiar  to  this  par¬ 
ticular  series  is  the  fact  that  of  the  six  subjects,  three  showed 
no  continued  improvement  over  their  first  deviations,  while  the 
other  three  made  exceedingly  rapid  progress  and  soon  overcame 
their  small  initial  remainders.  In  no  other  series  have  so  large  a 
per  cent  of  the  subjects  failed  to  readjust.  The  conclusion  is  sug¬ 
gested  that  there  may  be  much  more  individual  variation  in  the 
extent  to  which  this  sort  of  tactual-kinaesthetic  factor  is  effective, 
than  is  the  case  with  sight  and  touch. 

Such  a  conclusion  finds  support  from  the  consideration  of  par¬ 
ticular  cases.  Subject  T.  K.,  for  instance,  readjusted  very  rapidly, 
attaining  almost  100  per  cent  recovery  at  the  fourth  sitting.  He 
then  forged  on  ahead  beyond  or  to  the  left  of  the  actual  position  of 
the  finger,  showing  an  average  overcorrection  of  1.7  cm.  before 
he  settled  down  again  to  an  approximately  correct  localization. 
The  curves  of  the  other  two  who  readjusted  exhibit  merely  a 
slight  fluctuation  about  the  true  position  after  recovery  has  taken 
place. 

It  is  the  results  of  T.  H.  B.  which  most  strikingly  indicate 
how  helpless  an  individual  may  be  under  unusual  conditions  when 


THE  DEVELOPMENT  OF  A  NEW  SPATIAL  CO-ORDINATION  71 


left  to  depend  upon  kinaesthesis  alone.  Having  made  no  read¬ 
justment  during  nine  sittings,  at  the  10th  T.  H.  B.  was  permitted 
to  reach  out  to  what  he  thought  was  the  actual  position  of  his 
finger,  making  a  conscious  correction.  He  felt  sure  that  he  could 
do  this  accurately,  even  while  wearing  the  glasses.  His  first  con¬ 
fident  move  was  to  localize  buzzer  1  (position  53)  at  34,  or  9  cm. 
farther  away  than  he  had  previously  been  localizing  it !  During  20 
repeated  trials  he  was  unable  to  find  his  left  finger,  missing  it  on 
the  average  by  a  distance  of  16.7  cm.  to  the  right!  Astonished,  he 
came  back  the  next  day  determined  to  localize  it  accurately  this 
time,  but  only  to  repeat  the  performance  of  the  preceding  sitting 
during  12  more  trials.  It  was  only  when  directed  by  the  exper¬ 
imenter  to  reach  out  on  the  other  side  of  the  finger,  that  T.  H.  B. 
did  touch  it  by  accident.  After  this,  he  was  able  to  localize  it  with 
a  fair  degree  of  accuracy. 

A  comparison  of  the  average  results  for  the  three  subjects  in 
this  series  who  did  readjust,  with  those  of  other  series,  reveals 
of  course  a  striking  superiority  in  both  quickness  and  amount 
of  readjustment.  The  curves  for  series  E  in  Fig.  X  are  higher 
at  every  point  than  those  of  any  other  curves.  This  holds  true  even 
for  the  end  of  the  10  day  period,  for  on  the  average  an  excess 
of  readjustment  occurred.  While  the  10  day  remainders  for  series 
A-i,  B-i,  C,  and  D  are  respectively  12.5,  10.8,  1.0  and  .4  cm., 
that  for  series  E  is  +  .49  cm.,  representing  a  positive  extra  read¬ 
justment.  This  tendency  to  overcorrect  was  soon  checked  by  all 
of  the  subjects  who  showed  its  influence.  The  overcorrection, 

TABLE  VIII 


Tactual-Kinaesthetic  Clues  from  Left  Arm 


Sub¬ 

jects 

No.  of 
Sit¬ 
tings 

53 

Visual  Acc. 

66  79 

92 

Av.L.D. 

1st 

trial 

Av.Rem.  Total 

10  Per  Cent 

days  Readj. 

T.  K. 

10 

55-6 

66.7 

80.7 

93-6 

9-4 

+  1.7 

118 

W.  M.  S. 

10 

53-8 

66.4 

79.6 

92.2 

8.0 

.76 

9i 

M.  M. 

10 

52.0 

65-3 

78.9 

91.6 

10.0 

+•47 

104.2 

Average 

9 

9.1 

•49 

104.6 

N.  McL. 

9 

53-8 

65.8 

79.2 

92.0 

II.O 

97 

12 

R. 

10 

52.9 

66.2 

79.0 

92.3 

15.1 

13.0 

13 

F.  H.  B. 

,  11 

54-5 

66.9 

80.1 

92.9 

II. I 

9.6 

13.6 

Average 

12.4 

10.8 

12.9 

72 


MARGARET  WOOSTER 


Www^vvw' - - 

•A. 

r 

Standard.  • 

oca  C3C3 

With  knowledge 
•Without  knowUAq 
Undlstorteil 


- Auditory 

Tactual 


- Visu  aA 

— —  Tactual - 

kimaesthetU 


t — i — i — i — i — T 

1ai2  a  4-  5.  b  7 
NirmW  of  sitTi'aq 

Fig.  X.  Group  Curves. 


THE  DEVELOPMENT  OF  A  NEW  SPATIAL  CO-ORDINATION  73 

then,  indicates  apparently  nothing  more  than  an  unusually  strong 
impulse  toward  readjustment. 

In  considering  this  striking  superiority  of  the  tactual-kin- 
aesthetic  factor  it  must  be  held  in  mind  that  we  have  after  the 
first  sittings  another  factor  lending  its  weight  to  the  already 
strong  influence  of  the  tactual-kinaesthetic  clues  from  the  left 
arm.  This  comes  from  the  fact  that  as  soon  as  the  left  finger 
is  accidentally  touched  by  the  right  arm,  we  have  the  operation 
of  the  direct  contact  factor  the  influence  of  which  was  seen  to  be 
so  great  in  series  C.  It  is  no  wonder,  then,  that  after  actual  con¬ 
tact,  readjustment  is  completed  almost  immediately. 


TABLE  IX 

Summary  of  Results  for  All  Series 


No.  of  Factor  or 
Series  Condition 

No.  of 
Sub- 
j  ects 

Av.  No. 
Sit¬ 
tings 

Ini¬ 

tial 

L.D. 

Rem.  Rem. 
10  da.  Total 

Percent  Percent 
Readj.  Readj. 
10  da.  Total 

Mean 
Dev. 
10  da. 

Standard 

A- 1 -a  with 

•Knowledge 

7 

cm. 

19.1 

cm. 

12.5 

cm. 

8.7 

35-5 

56.0 

cm. 

8.0 

Without 

A-i-b  Knowledge 

4 

17.7 

10.6 

9.1 

38.8 

(47) 

10.0 

A-i  (a  &  b) 

ii 

22 

18.6 

1 1.8 

8.8 

36.0 

53-0 

8.8 

Sound 

B-i  of  Buzzer 

6 

18.3 

10.8 

7-7 

41-5 

(73) 

10.5 

Sound 

B-2  of  Bell 

6 

19.6 

8.0 

2.8 

64.0 

87.5 

16.5 

B  (I  &  2) 

12 

26 

19.0 

9.4 

5-3 

52.7 

80.0 

15-5 

Active 

C-2  Touch 

5 

10 

21.8 

1.02 

94-4 

3-9 

Passive 

C-i  Touch 

D  Sight 

7 

10 

17.6 

•4 

97.0 

4-3 

Tactual- 

E  Kinaesthetic 

3 

10 

9-1 

•5 

104.6 

9.0 

IV 

RETENTION  OF  THE  NEW  CO-ORDINATION 

The  question  as  to  how  long  the  new  spatial  coordination  will 
be  retained,  while  not  strictly  pertinent  to  our  main  problem  of 
determining  the  relative  influence  of  the  various  constituent  fac- 


74 


MARGARET  WOOSTER 


tors,  has  nevertheless  some  bearing  on  the  problem,  since  it  con¬ 
cerns  the  stability  of  the  new  habit. 

We  made  no  effort  systematically  to  investigate  the  amount 
of  retention  in  these  experiments,  or  its  relation  to  time  of  ac¬ 
quisition  or  the  sensory  factors  concerned.  But  some  weeks  after 
the  conclusion  of  the  experimental  series  we  gave  one  sitting 
each  to  such  subjects  as  were  still  available — seven  in  all. 

The  trials  were  given  in  the  same  manner  as  in  the  original 
sittings.  The  average  of  the  five  trials  for  each  position  was  taken, 
and  the  amount  of  readjustment  shown  was  calculated.  This  was 
compared  with  the  previous  highest  amount  of  readjustment 
to  show  the  per  cent  of  retention  of  the  habit. 

The  results  are  given  in  Table  X.  Some  individual  cases  of  re¬ 
tention  are  striking.  The  per  cent  retained  by  K.  E.  L.,  after  an 
interval  of  37  weeks,  was  77.  That  of  D.  S.,  after  24  weeks,  was 
90.  The  most  striking  case  of  all,  however,  is  that  of  H.  L.  K. 
After  an  interval  of  two  years  and  three  months  she  was  given  first 
the  test  for  visual  accuracy,  without  the  glasses.  In  this  test  her 
error  to  the  left  of  her  previous  normal  standard  of  visual  ac¬ 
curacy  was  3  cm.,  with  an  average  deviation  of  only  .9  cm.  On 
taking  the  20  trials  while  wearing  the  prismatic  glasses  H.  L.  K. 
showed  a  retention  of  47  per  cent  of  the  progress  made  two  years 
before.  Considering  the  fact  that  H.  L.  K.  had  originally  only  12 
sittings,  this  amount  of  retention  is  striking. 

The  results  for  all  of  the  subjects  who  took  the  retention  test 
point,  then,  to  a  high  degree  of  stability  and  persistence  in  the 
new  spatial  coordination. 


TABLE  X 

Retention 


Subject 

No.  of 
Sittings 

Series 

Approx.  No. 
of  Weeks’ 
Interval 

n  • 

jxeadj . 

Later 

Per  Cent 
Readj. 

Per  cent 
Retention 

D.  S. 

15 

A-i-b 

24 

57 

5i 

90 

T.  K. 

10 

E 

24 

1 18 

105 

89 

M.  L. 

6 

D 

30 

97 

78 

30 

T.  L. 

W. 

18 

C 

24 

78 

100 

78 

K.  E. 

L. 

3i 

B 

37 

82 

63 

77 

H.  L. 

K. 

12 

A-i-a 

116 

53 

25 

47 

E.  B. 

7 

D 

30 

97 

86 

88 

THE  DEVELOPMENT  OF  A  NEW  SPATIAL  CO-ORDINATION  75 


V 

DEGREE  OF  SPECIFICITY  OF  THE  NEW 

CO-ORDINATION 

Does  the  new  spatial  habit  acquired  by  the  subjects  in  this  ex¬ 
periment  carry  over  to  a  noticeable  extent  into  normal  situations  ? 
This  question  has  a  general  importance  theoretically  in  its  bear¬ 
ing  upon  the  whole  Kantian  and  modern  controversy  concerning 
the  generality  of  spatial  experience.  It  also  has  an  interest  for  the 
narrower  purposes  of  the  experimental  investigator  in  the  field 
of  space  perception.  Heretofore  the  attack  on  this  question  has 
been  in  general  theoretical  and  to  an  unfortunate  extent  contro¬ 
versial.  If  it  should  seem  possible  to  throw  light  on  the  problem 
by  some  such  simple  experimental  procedure  as  we  have  em¬ 
ployed,  then  there  would  be  promise  of  advance  in  future  ex¬ 
perimental  investigation  of  the  problem. 

It  proved  extremely  difficult  in  this  investigation  to  devise 
methods  that  would  secure  a  reliable  check  on  this  matter.  As 
soon  as  we  freed  the  subjects  from  the  rigid  conditions  imposed 
at  the  apparatus  in  order  to  observe  their  behavior  in  normal  sit¬ 
uations,  we  found  operating  many  obscure  factors  the  nature  of 
which  it  was  impossible  accurately  to  evaluate.  We  believe  how¬ 
ever  that  certain  tests  we  used  do  throw  some  light  on  the  prob¬ 
lem,  and  give  promise  that  in  the  future  genuinely  reliable  factual 
evidence  can  be  secured. 

Now  if  the  particular  spatial  habit  we  are  investigating  really 
does  function  in  general  situations,  we  should  find  the  following 
conditions  to  hold : 

1.  Subjects  wearing  the  glasses  at  the  apparatus  should  not 

find  the  new  o  J‘  Ttion  seriously  interfered  with  should  any 
change  in  the  gent*^  cy  situation  be  made. 

2.  On  the  removal  of  the  glasses  the  continued  functioning 
of  the  new  habit  should  manifest  itself  in  a  disturbance  of  the 
old  or  established  manner  of  reaction.  This  should  hold  not  only 
at  the  apparatus  table  but  for  attempts  to  localize  objects  in  or¬ 
dinary  situations. 


76* 


MARGARET  WOOSTER 


3.  Practiced  subjects  wearing  the  glasses  should  localize  or¬ 
dinary  objects  with  smaller  error  than  unpracticed  subjects. 

4.  Practiced  subjects  wearing  glasses  should  be  able  to  walk 
about  a  building  with  more  ease  and  efficiency  than  unpracticed 
subjects. 

These  four  general  criteria  we  applied  in  our  investigation.  In 
the  first  place  in  order  to  find  out  whether  a  change  in  the  general 
sensory  situation  interfered  with  the  new  coordination,  we  adopt¬ 
ed  the  following  procedure.  For  three  of  the  groups  at  the  con¬ 
clusion  of  the  trials  with  distorted  vision,  the  chair  in  which  the 
subject  sat  was  shifted  18  cm.  to  the  right,  and  localizations  were 
obtained  as  before  with  the  subject  reacting  from  the  new  posi¬ 
tion.  Now  if  the  new  habit  was  formed  merely  on  the  basis  of  a 
definite  position,  with  definite  tactual  and  kinaesthetic  stimuli,  it 
might  be  expected  that  it  would  be  seriously  disturbed  or  even  lost 
were  a  new  position  assumed.  The  shift  in  position  of  the  chair, 
however,  made  no  significant  difference  in  the  reactions  for  any  of 
the  20  subjects  who  took  this  test.  For  five  subjects  in  the  stand¬ 
ard  series,  ten  in  the  sound  series,  and  five  in  the  sight  series,  the 
average  difference  between  the  last  five  trials  for  the  shifted 
position  is  only  .3  cm.  This  small  difference  is  positive,  or  in  the 
direction  in  which  improvement  would  be  expected.  There  is, 
moreover,  a  negligible  amount  of  individual  variation,  the  dif¬ 
ference  being  very  small  in  every  case.  Flence  the  readjustment 
is  general  in  the  sense  of  not  being  limited  to  any  particular 
part  of  the  apparatus. 

To  answer  the  second  question  two  different  procedures  were 
adopted.  First  the  glasses  were  removed  from  the  subject  im¬ 
mediately  at  the  close  of  the  last  sitting  with  distorted  vision. 
Then,  still  seated  at  the  apparatus  he  was  required  to  localize 
the  buzzers  as  they  appeared  to  him  visually,  in  the  same  manner 
as  before,  but  without  the  glasses,  and  of  course  without  seeing 
his  finger. 

If  the  readjustment  had  been  a  function  merely  of  the  partic¬ 
ular  conditions  of  the  practice  series,  with  glasses  worn,  these 
localizations  with  normal  vision  would  have  been  objectively 
correct,  i.  e.,  the  subject  would  have  localized  the  buzzers  with 


THE  DEVELOPMENT  OF  A  NEW  SPATIAL  CO-ORDINATION  77 


approximately  the  same  degree  of  accuracy  as  in  the  trials  for 
normal  visual  accuracy  given  at  the  beginning  of  his  sittings. 

All  of  the  23  subjects  tested  in  this  way,  however,  made  a 
large  error  to  the  left  of  their  standard  for  normal  accuracy.  For 
five  subjects  in  series  B,  six  in  series  C,  nine  in  series  D,  and 
three  in  series  E,  to  whom  the  test  was  given,  the  average  error 
to  the  left  was  9.3  cm.  This  means  that  the  subjects,  having 
grown  accustomed  while  wearing  the  glasses  to  localizing  the 
buzzers  by  reaching  out  some  distance  to  the  left  of  where  they 
looked  to  be,  now  retained  the  habit  when  the  glasses  were  re¬ 
moved,  and  reached  out  confidently  to  the  left  of  where  the  ob¬ 
jects  objectively  were.  If  the  new  habit  had  functioned  in  full 
strength  without  the  prisms,  then  the  average  error  to  the  left 
would  have  been  14.8  cm.,  the  average  amount  of  improvement 
shown  during  the  sittings  by  these  23  subjects.  That  it  was  in 
fact  9.3  cm.  (or  62  per  cent  of  the  original  amount)  indicates 
a  striking  degree  of  transfer  of  the  new  formed  habit  to  the 
normal  situation,  considering  the  strength  of  the  customary  or 
old  association  between  object  seen  and  reaching  movement, 
which  on  the  removal  of  the  glasses  would  be  expected  to  exert 
a  strong  influence. 

The  other  procedure  adopted  for  determining  the  existence  of 
an  after  effect  from  the  wearing  of  the  glasses  was  carried  out 
away  from  the  apparatus.  The  subject,  still  wearing  the  glasses, 
was  seated  at  an  ordinary  study  table  and  directed  to  reach  out 
and  touch  with  the  index  finger  certain  objects  which  lay  on  the 
table — an  eraser,  an  ink  bottle,  and  a  thimble.  This  each  subject 
was  able  to  do  accurately,  after  a  few  trials  to  overcome  the 
small  error  to  the  right  that  he  still  made.  Now  the  subject  was 
asked  to  keep  on  reaching  out,  touching  the  objects  every  few 
seconds,  and  not  stopping  when  the  glasses  were  removed.  When 
he  had  started  localizing  the  objects  in  this  manner,  the  ex¬ 
perimenter  quietly  removed  the  glasses.  For  two  of  the  four  sub¬ 
jects  given  this  test  the  after  effect  was  striking.  These  two, 
T.  L.  W.  and  K.  E.  L.,  continuing  to  reach  out  in  the  same  way, 
missed  the  objects  each  time  by  from  two  to  four  cm.  to  the 
left,  although  they  could  plainly  see  their  hands  going  in  the 


78 


MARGARET  WOOSTER 


4 


wrong  direction.  They  were  surprised  and  amused  at  the  result. 
Both  reported  a  queer  “pull”  to  the  left  and  a  feeling  of  effort  or 
strain  as  if  something  were  holding  them  back.  Thus  in  spite  of 
the  existence  of  a  sharp  conflict  between  the  established  system 
of  localization  and  the  newly  acquired  space  habit,  the  latter  con¬ 
tinued  to  exert  an  influence  in  this  everyday  situation.  Moreover 
it  required  a  number  of  trials  for  both  subjects  before  they 
could  again  reach  out  and  touch  the  objects  accurately. 

For  the  two  subjects  whose  normal  reactions  were  not  thus  in¬ 
fluenced,  it  seems  that  the  sight  of  the  arm  and  hand  in  reaching 
out  may  have  supplied  an  overwhelmingly  powerful  stimulus  to 
unconscious  correction  to  the  right  while  the  movement  was  still 
under  way.  Even  for  the  subjects  who  did  feel  the  after  effects 
the  error  was  so  small  that  it  would  have  led  to  no  difficulty  in 
making  practical  adjustments  unless  movements  of  great  accuracy 
were  required;  and  it  is  quite  possible  that  the  effect  was  with 
them  only  transitory.  None  of  the  other  subjects  after  the  removal 
of  the  glasses  reported  any  interference  with  normal  reactions. 

Even  if  the  after-effect  is  slight  and  perhaps  transitory,  how¬ 
ever,  this  test  is  significant  in  showing  definitely  that  even  such 
a  rapidly  acquired  and  simple  spatial  coordination  as  this  may 
function  effectively  enough  to  interfere  with  the  longstanding 
habits  of  reaction.  It  is  unfortunate  that  the  test  was  devised  too 
late  to  give  to  a  larger  number  of  subjects.  Together  with  the 
test  at  the  apparatus  however  it  furnishes  clear  evidence  that  the 
new  habit  does  exert  an  influence  on  normal  reactions. 

Our  third  criterion,  that  subjects  who  had  learned  to  localize 
the  buzzers  more  or  less  correctly  while  wearing  the  glasses, 
should  be  able  with  the  glasses  on,  if  the  habit  is  general  and 
not  specific,  to  localize  ordinary  objects  with  either  no  error  or 
a  smaller  error  than  unpracticed  subjects,  we  subjected  to  test 
in  two  ways.  First,  we  had  the  subject  sit  at  a  study  table,  and, 
wearing  the  prismatic  glasses,  localize  objects  placed  in  definite 
positions  in  front  of  him.  Second,  we  had  him  walk  about  the 
room,  pick  up  objects,  walk  down  a  long  hall  and  the  like,  while 
we  carefully  observed  his  behavior. 

For  the  test  at  the  study  table  we  first  tried  the  following 


THE  DEVELOPMENT  OF  A  NEW  SPATIAL  CO-ORDINATION  79 

plan.  Five  objects, — two  ink  bottles  of  different  size  and  shape,  an 
eraser,  a  small  box,  and  a  thimble  were  placed  in  definite  posi¬ 
tions  on  the  table,  about  20  cm.  apart,  and  from  25  to  40  cm. 
from  the  edge.  The  subject,  wearing  the  glasses,  was  seated  in 
front  of  these  objects,  with  his  right  arm  resting  on  the  table 
parallel  to  the  front  edge.  He  was  instructed  to  reach  out  at  a 
natural  rate  of  movement  and  localize  the  object  as  it  appeared 
to  him  with  his  index  finger.  The  experimenter  first  named  the 
object,  and  then  at  the  signal  “go”  the  subject  reached  out,  letting 
his  finger  rest  where  it  happened  to  fall  until  the  experimenter 
had  noted  in  centimeters  the  amount  of  error  to  the  right. 

The  first  tests  given  with  this  method  showed  it  to  be  un¬ 
reliable.  The  errors  were  found  to  be  very  small  and  to  decrease 
markedly  after  the  first  trial.  But  far  from  indicating  a  transfer 
effect  this  only  showed  that  a  powerful  factor  was  operating 
within  the  time  of  the  test  to  decrease  the  amount  of  error.  This 
factor  seemed  evidently  to  be  the  sight  of  the  arm,  which,  after 
the  reaching  movement  was  started,  would  serve  as  a  strong 
stimulus  to  correction  to  the  left.  Such  a  conclusion  is  in  line  with 
the  statement  of  a  number  of  the  subjects  that  although  they  tried 
honestly  to  locate  the  object  as  it  looked  to  them,  they  felt  a  strong 
“muscular  urge”  or  “pull”  to  the  left  against  which  they  had  to 
resist. 

With  the  idea  of  at  least  partially  obviating  such  a  tendency 
to  correct  and  thus  of  getting  a  measure  of  the  transfer  effect, 
we  hit  on  the  plan  of  having  later  subjects  reach  out  very  quickly 
to  the  object,  believing  that  there  would  thus  be  much  less  likeli¬ 
hood  of  the  direction  of  the  movement  being  changed,  once 
started. 

Twenty-seven  subjects  took  the  test  in  this  form.  The  numerical 
results  for  all  individuals  are  given  in  Table  XI,  p.  81.  Although 
two  trials  were  given  for  each  object  only  the  first  is  given  here. 
In  practically  all  cases  the  error  was  much  less,  approaching 
zero,  on  the  second  trials.  Since  there  was  considerable  variation 
in  the  position  of  the  subject’s  chair,  his  distance  from  the  ob¬ 
jects,  and  the  order  in  which  they  were  named,  these  results  are  a 
very  rough  measure  only  of  the  relative  amount  of  error,  and  it 


8o 


MARGARET  WOOSTER 


would  be  useless  to  attempt  to  deal  with  group  averages  and  com¬ 
parisons.  The  individual  results,  however,  are  worth  studying. 

The  objective  errors  due  to  the  prismatic  distortion  would 
have  been  from  20  to  35  cm.,  according  to  the  position  of  the 
objects.  But  the  errors  shown  in  the  table  are  very  much  less. 
The  smallness  of  the  errors  however  can  not  be  due  primarily 
to  transfer.  This  is  shown  in  the  first  place  by  the  fact  that  the 
error  markedly  decreased  after  the  very  first  trial.  For  example : 
for  the  first  object  the  error  of  E.  B.  in  the  Tactual  Series  is 
20  cm.  and  for  the  second  object  only  7  cm.  For  F.  in  the  Visual 
Series  the  error  for  the  first  is  15  cm.  and  for  the  second  2  cm. 
Subject  F.’s  remark,  “I  feel  an  irresistible  pull  to  the  left,”  in¬ 
dicates  the  nature  of  the  stimulus  which  influenced  other  subjects 
though  in  lesser  degree,  to  decrease  their  errors.  Evidently  the 
sight  of  the  arm  in  reaching  and  the  visual  perception  of  the 
discrepancy  between  object  and  localizing  movement,  initiated 
kinaesthetic  impulses  so  strongly  in  conflict  with  the  reaction 
originally  released  as  to  modify  its  direction. 

A  second  type  of  evidence  that  the  smallness  of  the  errors  is 
not  the  direct  result  of  transfer  of  the  new  space  habit,  lies  in  the 
consideration  that  there  is  no  apparent  relation  between  the 
amount  of  error  in  this  test  and  either  length  of  practice  or  the 
amount  of  readjustment  attained.  The  results  of  M.  W.  and  M.  K. 
in  the  Visual  Series  illustrate  this  point.  M.  W.,  after  63  sittings 
and  complete  readjustment,  still  made  an  extremely  large  error; 
while  M.  K.,  who  took  only  10  sittings  and  showed  very  little 
readjustment,  made  much  smaller  errors,  and  these  were  quickly 
eliminated. 

The  main  indication,  however,  that  the  transfer  effect  is  not 
great  in  this  test  comes  from  comparison  with  the  results  of  an 
unpracticed  group.  Nine  students  who  had  heard  of  the  glasses 
but  had  never  worn  them  before,  were  given  the  same  test  at  the 
study  table  but  this  time  with  four  objects  instead  of  five.  From 
the  results  in  Table  XII,  p.  81,  we  might  at  first  glance  conclude 
that  the  regularly  larger  errors  are  due  to  lack  of  practice  with 
the  glasses.  But  in  the  first  place  it  is  seen  that  there  is  the  same 
decrease  with  successive  trials  as  in  the  practiced  group,  and  the 


THE  DEVELOPMENT  OF  A  NEW  SPATIAL  CO-ORDINATION  81 


TABLE  XI 

Initial  Errors  to  Right  in  Centimeters  for  Specificity  Test  at  Study  Table. 

No  Screen,  Quick  Reaction. 


Group 

Subject 

Objects 

Number  Average 
of  Total 

Sittings  Rem. 

i 

2 

3 

4 

5 

Standard 

0.  B.  B. 

9 

10 

ii 

14 

22 

9-5 

W.  A.  0. 

4 

4 

5 

27 

3-5 

Auditory 

C.  W.  L. 

16 

12 

12 

0 

4 

45 

4.2 

F.B. 

6 

3 

0 

0 

10 

25 

i-3 

K.  E.  L. 

9 

13 

9 

7 

4 

3i 

3-8 

C.  S. 

0 

0 

0 

o 

0 

25 

.2 

M.  M. 

14 

10 

8 

10 

2 

40 

3-6 

Visual 

M.  C. 

3 

4 

2 

7 

3 

10 

4-5 

F.  D. 

7 

9 

4 

2 

6 

ii 

•5 

D.  B. 

6 

6 

4 

3 

3 

13 

2.0 

M.  B. 

2 

2 

4 

2 

3 

10 

.2 

F. 

15 

2 

2 

I 

0 

10 

•9 6 

M.  K. 

ii 

12 

7 

2 

18 

10 

18.0 

T.  L.  W. 

15 

7 

12 

7 

3 

18 

i-4 

R.  D. 

8 

3 

6 

5 

7 

IO 

10.2 

Tactual 

J.  L.  B. 

13 

15 

16 

12 

19 

17 

1.4 

P.  J.  R. 

7 

4 

3 

4 

9 

IO 

2.3 

H.  G. 

ii 

3 

2 

3 

4 

IO 

.2 

A.  D.  U. 

9 

6 

4 

4 

2 

12 

.2 

E.  B. 

5 

20 

4 

7 

7 

•5 

P.  I. 

3 

7 

0 

4 

12 

7 

1. 1 

J.  H.  B. 

2 

13 

7 

i 

6 

5 

•45 

M.  P. 

4 

4 

8 

0 

0 

6 

4 

Tactual- 

T.  K. 

ii 

12 

ii 

9 

IO 

i -7 

Kinaesthetic 

W.  S. 

IO 

12 

13 

7 

16 

IO 

.76 

M.  My. 

12 

4 

4 

13 

14 

IO 

47 

TABLE  XII 


Errors  to  Right  in  Specificity  Test.  No  Screen.  Quick  Reaction. 

Unpracticed  Group. 


Objects 

Subject 

1 

2 

3 

4 

E 

14.0 

21.0 

5-0 

12.0 

W 

12.0 

4.0 

2.0 

6.0 

F 

9.0 

3-0 

2.0 

9.0 

FI 

15.0 

12.5 

0.0 

8.0 

R 

12.0 

13.0 

7-5 

II-5 

Fr 

14.0 

16.0 

0.0 

3-0 

H 

12.0 

3-0 

11.0 

B 

12.0 

11.0 

2.0 

4.0 

S 

18.0 

12.0 

4-5 

16.0 

Average 

13-3 

10.4 

2.9 

8.9 

82 


MARGARET  WOOSTER 


same  individual  variation.  In  the  second  place  it  is  true  that  the 
experimenter  with  the  unpracticed  group  took  more  pains  to 
impress  on  the  subjects  the  point  that  they  were  not  to  correct 
to  the  left.  In  the  third  place  the  errors,  even  though  relatively 
larger  than  for  the  practiced  group,  are  still  on  the  average  half 
or  less  than  half  what  the  objective  uncorrected  error  would 
have  been. 

It  follows  then  that  our  second  plan  for  securing  a  fair  measure 
of  the  transfer  effect  was  unsuccessful,  and  that  so  far  there  is  no 
clear  evidence  that  the  new  habit  functions  in  every-day  situa¬ 
tions. 

A  third  plan  was  tried  after  the  regular  series  had  been  con¬ 
cluded.  The  experience  of  the  writer,  M.  W.,  pointed  to  a  possible 
source  of  error  in  the  fact  that  a  more  rapid  rate  of  movement 
was  prescribed  for  the  test  than  the  natural  rate  employed  during 
the  original  building-up  of  the  habit  at  the  apparatus.  M.  W. 
did  not  complete  her  readjustment  and  take  the  tests  with  ob¬ 
jects  at  the  study  table  until  after  practically  all  the  other  subjects 
had  finished.  She  found  then  that  when  she  reached  out  very 
quickly  to  localize  the  objects,  she  missed  them  on  the  average  by 
as  much  as  iy  cm.  But  when  later  she  tried  reaching  out  at  a 
natural  rate  of  movement  she  missed  them,  if  at  all,  by  only  one 
or  two  centimeters !  The  same  results  were  obtained  at  several  later 
times.  This  suggested  that  the  other  subjects  may  have  been 
making  more  than  their  natural  amount  of  error,  since  the  di¬ 
rections  had  been  explicit  to  move  very  quickly.  Such  a  con¬ 
clusion  is  in  line  with  the  work  of  Woodworth  on  movement. 
He  found  that  a  simple  movement  automatically  performed  at 
a  natural  rate,  was  made  with  much  less  accuracy  when  the  rate 
was  greatly  increased.1 

It  seemed  likely,  then,  that  our  test  of  the  generality  of  the 
new  coordination  had  not  been  a  fair  one.  An  attempt  was  made 
to  check  the  accuracy  of  this  conclusion  by  giving  the  test  in 
a  modified  form  to  four  students  who  had  formerly  served  as 
subjects  and  had  attained  varying  per  cents  of  readjustment. 

1  Woodsworth,  R.  S.  “Le  Mouvement.”  Paris,  1903.  Ch.  XV. 


THE  DEVELOPMENT  OF  A  NEW  SPATIAL  CO-ORDINATION  83 


First,  wearing  the  glasses,  they  practiced  making  localizations 
at  the  apparatus,  with  sight  of  the  finger,  until  a  test  given  by  the 
experimenter  showed  that  they  could  localize  the  buzzers  with 
a  constant  error  of  less  than  one  centimeter  to  the  right.  (Since 
readjustment  takes  place  very  rapidly  in  the  sight  series,  and 
since  the  four  subjects  reached  out  as  often  and  for  as  long  a 
practice  period  as  they  pleased,  it  only  required  from  one  to 
four  sittings  to  make  complete  readjustment  again.)  The  sub¬ 
jects  were  then  given  the  tests  with  objects  at  the  study  table, 
this  time  with  two  changes.  First,  they  reached  out  at  a  natural 
and  not  a  forced  rate  of  movement.  Second,  the  movement  of 
the  hand  and  arm  in  reaching  was  carefully  screened  by  a  card¬ 
board  cover  so  that  the  finger  was  seen  only  when  the  reaching 
movement  was  concluded.  The  last  precaution  was  observed  to 
aid  in  obviating  the  incentive  to  correction  afforded  by  the  sight 
of  the  arm. 

The  results  as  given  in  Table  XIII  are  from  too  few  subjects 
to  justify  definite  conclusions.  While  it  is  worthy  of  note  that 
none  of  the  errors  are  significantly  larger  than  in  the  preceding 
test,  there  is  still  no  evidence  on  the  basis  of  results  for  these 
four  subjects  that  the  additional  precautions  taken  (of  using  the 


TABLE  XIII 
Specificity  Test 

At  Study  Table — with  Cardboard  Screen — Natural  Rate  of  Movement. 


Per  cent  Per  Cent 

Approximate 

Subject 

Readj.  Readj. 

Errors 

in  Cm. 

to  R.  of  Objects 

Original  With  Practice 

1 

2 

3 

4 

T.  L.  W. 

100  100 

7 

6 

5 

K.  E.  L. 

10  100 

5 

3 

3 

2 

H.  L.  K. 

40  100 

7 

0 

9 

6 

E.  S.  R. 

53  100 

12 

14 

13 

11 

Average 

7-7 

5.61 

7-8 

6.0 

Average  Error 

in  Cm.  for  Objects 

Group 

No.  Subjects 

1 

2 

3 

4 

With  Screen 

9 

18.0 

230 

10.6 

174 

Without  Screen 

9 

130 

10.4 

2.9 

8.9 

84 


MARGARET  WOOSTER 


screen  and  adopting  a  natural  rate  of  movement)  affected  the 
results.2 


TABLE  XIV 

Specificity  Test  at  Study  Table,  with  Cardboard  Screen.  Natural  Rate  of 

Movement.  Unpracticed  Subjects. 


Subject 

1 

Error  to  Right  in  Cm. 

2  3 

4 

G.  C. 

20 

24 

15 

L.  M. 

26 

25 

16 

22 

G.  K. 

18 

20 

13 

14 

R.  W. 

17 

16 

7 

13 

W.  B. 

19 

24 

7 

21 

H.  C. 

28 

28 

16 

21 

N.  G. 

26 

22 

16 

16 

E.  B. 

22 

25 

12 

1 7 

R.L. 

7 

21 

9 

18 

Average 

18.1 

22.8 

10.6 

17.4 

Comparison  of  the  results  of  this  modified  test  with  practiced 
subjects  with  results  of  the  same  test  given  to  nine  unpracticed 
subjects  does  seem,  however,  to  reveal  significant  differences. 
Table  XIV  gives  the  individual  results. 

On  the  face  of  it  these  results  would  indicate  that  the  larger 
amount  of  error — over  twice  as  great  as  for  the  practiced  sub¬ 
jects — must  be  correlated  with  lack  of  practice,  and  hence  that 
there  is  evidence  of  decided  transfer  of  the  space  habit  to  the 
study  table  situation.  Again,  however,  the  experimenter  here 
took  special  care  to  instruct  the  unpracticed  subjects  not  to  cor¬ 
rect  to  the  left,  but  to  locate  the  objects  as  they  appeared  to  be — 
a  care  not  exercised  in  the  same  degree  with  the  practiced  sub¬ 
jects.  This  source  of  error  alone  may  possibly  account  for  the 
difference  in  the  results.  We  may  say,  however,  that  this  situa¬ 
tion  does  furnish  some  evidence,  though  of  doubtful  value,  for 
transfer. 

It  is  not  surprising  that  if  we  were  unable  to  get  conclusive  evi¬ 
dence  for  transfer  to  ordinary  situations  from  the  test  with  objects 

2  That  the  use  of  the  screen  does  help  to  obviate  the  tendency  to  correct 
is,  however,  shown  in  a  comparison  of  the  results  of  larger  groups  of  un¬ 
practiced  subjects,  who  were  later  given  short  tests  at  the  study  table.  The 
results  are  as  follows: 


Average  Error  in  Cm.  for  Objects: 

Group  No.  Subjects  1234 

With  Screen  9  18.0  23.0  10.6  17.4 

Without  Screen  9  13.0  10.4  2.9  8.q 


THE  DEVELOPMENT  OF  A  NEW  SPATIAL  CO-ORDINATION  85 

at  the  study  table,  we  were  similarly  unable  to  observe  any  clear 
differences  in  the  behavior  of  practiced  and  unpracticed  subjects 
while  walking  about  the  room.  Both  practiced  and  unpracticed 
subjects  managed  to  walk  about  and  perform  ordinary  acts  with 
no  serious  mishaps.  In  general  for  both  there  was  a  constant 
tendency  to  walk  to  the  right  and  to  reach  out  to  the  right  of  the 
actual  position  of  objects.  The  greater  the  distance  and  the 
quicker  the  movement  the  greater  were  the  errors.  Errors  in 
reaching  were  also  much  greater  when  the  movement  of  the 
hand  was  not  seen.  There  was  for  most  subjects  swaying  and  un¬ 
steadiness  in  walking,  as  long  as  visual  guidance  was  employed, 
and  general  hesitation  and  confusion  in  movement.  Some  sub¬ 
jects  made  much  greater  errors  to  the  right  in  reaching  for  ob¬ 
jects  than  others;  but  among  the  ten  unpracticed  subjects  thus 
observed,  the  errors  varied  in  extent  practically  as  much  as  with 
practiced  subjects. 

We  might  conclude  that  these  observations  indicate  that  there 
is  no  transfer  to  everyday  situations.  Two  considerations,  how¬ 
ever,  show  that  this  conclusion  would  not  be  justified.  In  the 
first  place,  unpracticed  subjects  in  these  everyday  situations  are 
under  the  influence  of  very  powerful  sensory  incentives  to  im¬ 
mediate  readjustment.  If  the  mere  visual  perception  of  amount 
of  error,  as  in  Series  D,  is  a  strong  incentive,  how  very  much 
stronger  will  be  the  perception  of  the  discrepancy  in  the  total 
sensory  situation !  In  the  second  place  even  were  an  actual  transfer 
effect  present  in  the  case  of  practiced  subjects,  it  might  be  obscured 
by  the  operation  of  other  factors.  For  instance,  subjects  who  had 
readjusted  to  the  spatial  situation,  as  far  as  direction  was  con¬ 
cerned,  might  still  be  unable  to  judge  distance  correctly.  The 
writer  found  that  many  of  her  errors  were  made  in  estimating 
depth  and  distance,  not  direction.  For  instance,  it  was  very  dif¬ 
ficult  to  walk  downstairs  with  visual  guidance,  not  because  of  any 
temptation  to  go  to  the  right,  but  because  the  steps  looked  curved 
and  much  lower  than  they  actually  were,  and  there  was  con¬ 
sequently  an  inappropriate  muscular  reaction. 

Much  of  the  uncertainty  of  the  practiced  subjects  may  have 
been  due,  then,  to  this  difficulty  in  adjustment  to  changed  dis- 


86 


MARGARET  WOOSTER 


tance  relations.  Other  disturbing  factors  are  the  limiting  of  the 
field  of  vision  by  the  frame  of  the  glasses,  and  the  fact  that  the 
stationary  prisms  in  front  of  the  moving  eyes  produced  dizziness 
and,  with  a  few  subjects,  even  nausea. 

But  while  our  observation  of  the  general  behavior  of  the  sub¬ 
jects  in  ordinary  situations  offers  no  clear  negative  evidence  on 
the  question  of  the  general  nature  of  the  new  space  habit,  neither 
does  it  offer  positive  evidence. 

While  in  general  it  seems  that  transfer  to  ordinary  situations 
is  slight,  if  existent  at  all,  there  is  evidence  that  there  are  indi¬ 
vidual  differences  in  the  matter.  Some  subjects  consistently  made 
large  errors  both  at  the  study  table  and  in  walking  about  the 
room,  while  others  made  negligible  errors,  or  none. 

Subject  C.  S.  of  the  Auditory  Series  is  one  for  whom  the  new 
habit  seemed  to  carry  over  effectively  into  ordinary  situations. 
She  had  learned  to  localize  the  buzzers  without  error  at  the  ap¬ 
paratus  in  25  sittings.  At  the  study  table  she  reached  out  with  per¬ 
fect  ease  for  the  objects,  making  absolutely  no  error  even  on  the 
first  trial.  (See  Table  XI).  Considering  the  limitation  of  the 
visual  field  by  the  glasses,  she  made  her  way  about  the  room  with 
ease,  making  no  mistakes  in  direction. 

Subjects  M.  B.  of  the  Visual  Series,  with  ten  sittings,  may  also 
possibly  have  retained  the  effects  of  practice  in  normal  situations. 
Her  errors  at  the  study  table  were  all  small  (the  first  being  only 
4  cm.)  and  soon  disappeared.  M.  B.  found  it  “perfectly  easy  to 
get  around  the  room  and  see  objects.”  She  walked  about  con¬ 
fidently,  picking  up  objects  here  and  there  and  reaching  out  for 
door  knobs  and  the  like  without  any  observable  sign  of  a  tendency 
to  go  to  the  right.  She  reported  that  things  looked  natural  to  her, 
and  that  when  she  reached  out  to  touch  things  they  “seemed  in 
the  right  position.”  She  said  she  felt  no  muscular  strain  or  “pull” 
away  from  objects,  as  most  other  subjects  did. 

No  subjects  in  the  practiced  group  were  able  to  adapt  them¬ 
selves  so  well  to  ordinary  situations  as  M.  B.  and  C.  S.  It  must 
be  remembered,  however,  that  these  two  are  exceptions  in  the 
practiced  group,  and  that  others  in  that  group  constantly  made 
large  errors  in  direction.  In  the  case  of  subject  E.  B.  of  the 
Visual  Series,  for  instance,  the  new  habit  seemed  to  hold  only 


THE  DEVELOPMENT  OF  A  NEW  SPATIAL  CO-ORDINATION  87 

for  very  specific  situations.  E.  B.  had  made  a  readjustment  of  97 
per  cent  in  seven  sittings.  After  taking  the  trials  for  visual  ac¬ 
curacy  without  glasses  at  the  end  of  the  series,  she  found  that 
when  she  began  localizing  with  glasses  again  she  made  just  as 
large  an  error  to  the  right  as  at  the  beginning!  It  took  30  trials 
to  bring  her  up  again  to  her  newly  acquired  standard  of  correct 
localization.  Again  when  seated  at  the  study  table  she  missed  the 
first  object  by  20  cm.  but  the  error  quickly  decreased  in  the  fol¬ 
lowing  trials.  In  walking  about  the  room  with  the  glasses  on  she 
again  experienced  great  difficulty,  making  large  errors  constantly 
unless  she  went  very  slowly  and  caleulatingly. 

The  writer,  when  she  had  finally  attained  complete  readjust¬ 
ment  after  63  sittings,  found  great  difficulty  in  walking  about 
the  room  and  down  the  hall.  Unless  she  disregarded  the  looks  of 
things  and  trusted  to  the  established  kinaesthetic-tactual  habits, 
she  made  constant  errors  to  the  right  when  distances  of  several 
feet  were  invloved,  as  for  instance,  in  walking  rapidly  to  a  door 
knob  from  the  middle  of  the  room.  In  walking  down  a  long  hall 
she  bumped  into  the  right  wall  every  few  feet  unless  she  used 
her  right  arm  as  guide.  But  within  more  definitely  prescribed 
areas  her  errors  were  much  smaller.  In  fact  as  long  as  she  used 
a  natural  rate  of  movement  and  looked  carefully  at  the  objects 
she  was  reaching  for,  she  made  either  very  small  errors  or  none 
at  all.  Her  very  large  errors  at  the  study  table  (15  to  28  cm.) 
were  evidently  due  to  the  disturbing  effect  of  an  unnatural  rate 
of  speed,  for  when  she  reached  out  at  a  natural  rate,  even  with 
the  movement  of  her  arm  screened,  she  localized  the  objects  al¬ 
most  perfectly  even  on  the  first  trial.  In  general  whenever  she 
moved  about  the  room  naturally,  without  thinking  particularly 
what  she  was  doing,  she  found  herself  able  to  localize  correctly 
almost  any  object  she  wished  to  touch.  She  found  on  trial  that  she 
was  able  to-  serve  herself  at  the  table  without  difficulty,  reach  for 
the  salt,  put  sugar  into  her  coffee,  etc.,  without  any  false  move¬ 
ments.  It  was  only  when  she  moved  very  quickly,  or  approached 
objects  quickly  from  some  distance,  that  serious  errors  to  the 
right  were  made. 

The  conclusion  is  that  in  M.  W’s  case  the  new  habit  probably 


88 


MARGARET  WOOSTER 


functioned  to  a  considerable  extent  in  normal  situations  as  long 
as  the  general  kinaesthetic  setting  was  the  same  as  prevailed 
while  the  new  coordination  was  forming.  The  very  small  errors 
which  did  appear  were  easily  and  unconsciously  overcome  in  the 
making  of  practical  adjustments.  But  when  large  distances  were 
involved  the  error,  being  proportionately  greater,  would  inevita¬ 
bly  be  sufficiently  large  to  interfere  with  practical  accuracy, 
even  though  there  was  a  transfer  effect.  The  general  confusion, 
hesitation,  and  slight  dizziness  can  be  accounted  for  on  the  basis 
of  other  disturbing  factors  previously  mentioned. 

None  of  the  unpracticed  subjects  were  able,  judging  from  ap¬ 
pearances,  to  localize  objects  with  the  ease  and  naturalness  of 
M.  W.,  and  certainly  not  with  the  ease  of  C.  S.  and  M.  B.  More¬ 
over  the  unpracticed  subjects  were  unanimous  in  reporting  a  de¬ 
cided  “pull”  or  muscular  conflict  while  some  of  the  practiced  sub¬ 
jects,  among  them  the  three  just  named,  felt  no  such  muscular 
strain.  For  the  writer,  accurate  reaching  movements  were  made 
with  absolutely  no  feeling  of  strain  or  effort. 

We  may  conclude  that  for  some  subjects  at  least  there  is  evi¬ 
dence  that  the  newly  acquired  habit  of  judging  direction  in  visual 
space  does  function  in  normal  situations.  It  proved  impossible  to 
isolate  the  various  factors  involved  sufficiently  well  at  the  study 
table  to  test  out  accurately  the  transfer  effect  there,  yet  there 
is  some  evidence  for  it  even  from  those  tests.  More  accurate 
methods  are  needed  and  could  no  doubt  be  devised. 

The  consideration  of  individual  cases,  however,  both  at  the 
study  table  and  in  more  general  situations,  indicates  plainly  first 
that  there  may  be  a  pronounced  carrying  over  of  the  habit  in 
the  case  of  some  subjects;  second  that  a  slight  transfer  effect 
probably  exists  for  some  subjects  but  is  obscured  by  other  dis¬ 
turbing  factors;  and  third  that  there  are  probably  marked  in¬ 
dividual  differences  in  the  extent  to  which  the  new  habit  is  gen¬ 
eralized. 

The  general  conclusion  from  all  the  experiments  on  specificity 
is  that  the  new  space  habit  is  by  no  means  a  merely  limited  and 
specific  mode  of  functioning,  but  that  it  may  affect  reactions 
in  more  general  conditions  than  those  prevailing  in  the  original 


THE  DEVELOPMENT  OF  A  NEW  SPATIAL  CO-ORDINATION  bg 


experiment.  The  wider  significance  of  this  fact  is  contained  in 
the  statement  that  the  systems  of  retinal  and  general  kinaesthetic 
habits  involved  in  the  new  spatial  coordination  apparently  func¬ 
tion  to  a  greater  or  less  degree  in  general  situations.  This  con¬ 
clusion  must  be  put  forward  very  tentatively,  owing  to  the  un¬ 
satisfactory  nature  of  the  general  experimental  control. 

It  is  clear,  moreover,  that  the  amount  of  transfer  is  for  most 
subjects  not  very  marked.  In  view  of  the  fact  that  the  glasses 
were  worn  but  a  short  time,  we  would  not  expect  the  system 
of  habits  acquired  during  that  time  to  have  much  influence  on 
the  old  system  of  retinal-motor  habits  which  has  been  functioning 
since  infancy.  The  surprising  thing  is  that  there  is  any  inter¬ 
ference  at  all.  Considering  the  conditions  of  the  experiment  we 
have  here  a  remarkably  stable  and  well  organized  habit  system, 
which  functions  automatically  while  the  glasses  are  worn  and 
even  carries  over  to  some  extent  into  the  established  reaction 
system. 

Incidentally  it  is  interesting  to  note  that  the  new  reaction  pat¬ 
tern  did  not  disintegrate  between  trials,  but  carried  over  in  full 
strength  from  one  day’s  sitting  to  the  next,  in  spite  of  the  con¬ 
flicting  modes  of  adjustment  employed  meantime.  Thus  we  have 
two  distinct  sets  of  complex  retinal-motor  habits,  alternating 
at  short  or  long  intervals  according  to  the  stimulating  situation 
(whether  the  glasses  are  worn  or  not).  This  fact  is  suggestive 
in  connection  with  the  phenomena  of  alternating  personality,  in 
which  the  same  principles  operate  though  on  a  vastly  more  com¬ 
plex  scale. 


VI 

RELATION  OF  READJUSTMENT  TO  DEFINITE 
LOCALIZING  ACTIVITY 

A  complete  study  of  the  process  of  the  formation  of  a  new 
spatial  coordination  would  involve  an  examination  of  its  relation 
to  overt  motor  activity.  Is  readjustment  conditioned  by  active 
efforts  to  make  some  definite  motor  adjustments  to  the  new 


90 


MARGARET  WOOSTER 


situation,  or  may  it  occur  when  the  subject  takes  a  merely  pas¬ 
sive  attitude? 

It  was  our  original  plan  systematically  to  investigate  this  as¬ 
pect  of  the  problem.  This  we  could  do  by  giving  only  one  trial 
per  sitting  for  one  group  of  subjects,  and  comparing  the  results 
with  those  of  groups  having,  let  us  say,  20,  40,  and  80  trials  per 
sitting.  It  would  be  desirable  also  to  devise  a  method  of  response 
by  verbal  identification  instead  of  active  reaching.  We  did  not 
have  time  to  carry  out  this  plan. 

It  was  thought,  however,  that  some  light  might  be  thrown  on 
the  problem  (especially  in  so  far  as  it  concerns  reasons  for  read¬ 
justment  in  the  standard  series)  by  finding  out  whether  or  not 
any  readjustment  would  occur  while  the  subjects  merely  sat 
passively  without  making  any  overt  response  at  all.  It  was  not 
practicable  to  use  the  apparatus  for  this  purpose,  and  so  with 
the  four  subjects  used  the  procedure  was  as  follows  : 

The  subject,  wearing  the  prismatic  glasses,  was  first  given  a 
test  at  the  apparatus,  to  determine  his  average  linear  deviation 
for  each  of  the  four  buzzers.  He  reacted  by  movement  of  arm 
and  hand  as  in  preceding  series.  Three  trials  were  taken  for  each 
position. 

The  subject  was  then  seated  at  a  table  in  another  room.  After 
the  glasses  were  put  on  he  remained  there  passively  for  20  min¬ 
utes,  viewing  objects  in  the  room,  but  making  no'  overt  localizing 
movements  of  any  kind.  Ten  such  sittings  were  given.  At  the  close 
of  the  tenth,  the  subject  was  again  seated  at  the  apparatus,  and 
the  amount  of  deviation  determined  as  before. 

The  results  are  given  in  Table  XV.  A  number  showing  positive 
increase  is  preceded  by  a  plus  sign  and  one  showing  regression 
by  a  minus  sign.  Three  of  the  four  subjects  show  absolutely  no 
decrease  in  deviation  after  the  ten  “passive”  sittings.  One  made 
an  average  increase  of  two  cm.,  but  this  increase  occurred  for 
only  two  of  the  buzzers.  On  the  average,  there  was  even  a  slight 
regression  from  the  actual  position  of  the  buzzers. 

There  were  too  few  cases,  and  too  small  a  number  of  trials 
in  each  case,  to  justify  sweeping  conclusions.  Moreover  had 
the  sittings  been  taken  at  the  regular  apparatus,  and  had  they 
been  continued  longer,  the  results  would  have  been  more  con- 


THE  DEVELOPMENT  OF  A  NEW  SPATIAL  CO-ORDINATION  91 

elusive.  They  do,  however,  indicate  clearly  that  under  these  par¬ 
ticular  conditions  no  significant  readjustment  occurs  without 
definite  localizing  movements.  We  may  say  provisionally,  then, 
that  apparently  the  process  of  readjustment  to  the  new  spatial 
situation  is  conditioned  by  definite  and  overt  adaptive  movements 
on  the  part  of  the  subjects. 


TABLE  XV 

Difference  between  Initial  and  Final  Localizations 


Subject 

53 

66 

79 

92 

Av. 

C.  J.  W. 

+2.0 

—5-o 

—3-3 

+  -5 

—1-5 

0.  W. 

+1.6 

— 2.2 

+  1.0 

—  .8 

— 1.0 

A.  O.  U. 

+  -6 

.0 

+4-6 

+3-3 

+2.1 

J.  S. 

—  7 

—4.9 

—1.4 

—  -9 

—i-5 

VII 

SUMMARY  AND  CONCLUSIONS 

The  outcome  and  signficance  of  our  experiments  may  be  sum¬ 
marized  under  twelve  main  heads  as  follows : 

1.  No  readjustment  to  the  changed  visual  situation  occurred 
without  definite  reaching  movements  of  the  hand  while  the  eye 
was  fixed  on  the  visual  object.  Thus  the  development  of  the  new 
coordination  seems  to  be  conditioned  by  definite  localizing  activity 
on  the  part  of  the  subject.  The  process  of  forming  the  new  habit 
seems  to  consist  largely  in  the  association  of  visual  and  tactual 
stimuli  with  kinaesthetic  stimuli  involved  in  the  localizing  move¬ 
ments.  This  observation  is  entirely  in  accord  with  Stratton’s 
experience.  “It  was  repeatedly  noticed  in  the  course  of  the  ex¬ 
periment”,  he  says,  “that  the  total  experience  was  much  more 
harmonious  during  active  movements  of  my  body  than  when  I 
inactively  looked  upon  the  scene.”  And  again  “The  scene  it¬ 
self  became  more  my  own  by  acting  upon  it,  and  this  action 
reacted  to  bring  the  representation  of  my  body  into  harmonious 
relation  to  the  scene.” 

2.  There  was  a  progressive  readjustment  in  the  standard 


92 


MARGARET  WOOSTER 


series,  although  there  were  apparently  no  sensory  stimuli  indi¬ 
cating  the  actual  position  of  the  object.  This  seems  to  represent 
an  unconscious  adaptation  of  the  reaching  movements  to  the 
new  kinaesthetic  stimuli  from  the  eye  muscles.  In  other  words, 
pare  of  the  readjustment  that  occurred  was  not  a  reorgani¬ 
zation  of  response  with  respect  to  the  actual  position  of  the 
object,  but  represented  an  adaptation  to  particular  sensory  con¬ 
ditions  induced  by  the  wearing  of  the  prisms.  It  is  reasonable 
to  suppose  that  the  readjustment  in  the  standard  series  was  due 
to  the  tendency  of  the  subject  mechanically  to  react  with  the 
hand  in  response  to  the  old  habitual  concept  of  “front”  associated 
with  head  position,  rather  than  to  the  new  definition  of  “front” 
involved  in  the  altered  position  of  the  eyes  in  the  head.  If  so, 
this  would  indicate  that  when  there  is  even  a  slight  disturbance 
of  the  customary  relationship  between  ocular-motor  habits  and 
general  bodily  habits,  the  individual  mechanically  and  uncon¬ 
sciously  varies  his  reactions  in  such  a  way  as  to  bring  the  latter 
into  harmony  with  the  established  type  of  reaction.  In  any  case 
it  seems  that  slight  changes  in  the  delicate  muscular  mechanism 
regulating  the  eye  may  profoundly  influence  the  overt  reactions 
of  an  individual  although  he  may  be  entirely  unaware  of  the  effect 
on  his  behavior  of  the  new  kinaesthetic  stimuli. 

Experimental  verification  and  further  investigation  of  this  hy¬ 
pothesis  are  needed.  While  the  existence  of  this  hypothetical 
ocular-motor  stimulus  to  progressive  readjustment  has  presum¬ 
ably  interfered  with  the  quantitative  accuracy  of  our  measure¬ 
ments  of  the  relative  efficacy  of  various  sensory  factors,  yet  its 
existence  as  a  conditioning  factor,  if  well  established,  would 
still  be  profoundly  significant.  For  it  would  indicate  anew,  in  a 
striking  way,  the  extreme  intricacy  and  delicacy  of  the  com¬ 
plex  system  of  retinal  and  general  habits  which,  developing  and 
functioning  automatically,  constitutes  our  spatial  experience. 

3.  Subjects  in  the  auditory  series  in  which  the  sound  offered 
a  sensory  clue  to  the  actual  position  of  the  subject,  showed  on 
the  average  no  stronger  tendency  to  react  closer  to  that  actual 
position  than  those  in  the  standard  series.  There  may  be  individual 
cases  in  which  sound  was  effective  but  on  the  whole  the  conclusion 


THE  DEVELOPMENT  OF  A  NEW  SPATIAL  CO-ORDINATION  93 


is  justified  that  under  the  conditions  of  our  experiment  sound 
is  not  an  effective  factor  in  the  formation  of  the  new  spatial 
coordination. 

4.  When  contact  was  used  as  a  practical  check  on  the  efficacy 
of  the  localizing  movement,  a  new  habit  of  localization,  ob¬ 
jectively  correct,  was  very  rapidly  built  up.  Such  a  new  coor¬ 
dination  is  formed  on  the  basis  of  mere  chance  contact,  but  there 
was  no  regular  and  systematic  learning  until  the  subject  was 
allowed  each  time  to  check  the  accuracy  of  his  reaching  movement 
by  definite  exploratory  contact  with  the  buzzer.  The  combined 
factors  of  kinaesthesis  and  contact  then  proved  to  be  very 
important  in  the  formation  of  the  new  coordination. 

5.  Visual  perception  of  the  amount  of  error  served  as  the 
most  powerful  single  sensory  factor  in  the  development  of  the 
new  habit.  The  evidence  is  conclusive  that  in  our  experiment 
vision  was  at  least  as  efficacious  as  the  combined  tactual  and 
kinaesthetic  factors  involved  in  active  touch;  and  there  is  good 
evidence  that  it  is  definitely  a  more  efficacious  factor.  In  this 
regard  our  experiments  strongly  support  a  tentative  hazard  of 
Stratton’s  for  which  he  was,  on  the  basis  of  his  experiment,  un¬ 
able  to  adduce  direct  factual  evidence.  In  discussing  the  question 
as  to  whether  or  not  visual  direction  is  dependent  upon  tactual  di¬ 
rection,  he  says  “If  there  is  any  dependence  either  way  (which 
I  doubt)  the  evidence  seems  to  favor  the  primacy  of  sight.”  In 
his  own  experiment  there  are  a  number  of  indications  that  this 
is  the  case.  An  example  is  the  fact  of  stubborn  persistence  of 
the  “old”  localization  of  parts  of  the  body  not  visible.  Another 
is  the  reference  to  the  old  system  of  the  legs  in  motion  while  walk¬ 
ing,  if  not  in  the  visual  field  at  the  tune.  Evidently  the  direct  vis¬ 
ual  perception  of  the  amount  of  error  made  under  the  new  or 
disturbed  conditions  was  for  Stratton  as  for  our  subjects  an  ex¬ 
ceedingly  powerful  sensory  stimulus  to  new  adaptive  reactions. 
The  conclusion  is  strongly  suggested  that  if  it  had  been  possible 
to  isolate  the  contact  factor,  studying  its  effect  apart  from  the 
kinaesthetic  stimuli  involved  in  the  exploratory  movements  the 
“primacy  of  sight”  would  have  been  far  more  strikingly  demon¬ 
strated. 


94 


MARGARET  WOOSTER 


6.  By  far  the  most  rapid  acquisition  of  the  new  coordination 
occurred  in  the  tactual-kinaesthetic  series,  in  which  the  sensory 
clues  to  the  tactual  position  of  the  object  (left  finger  in  this  case) 
consisted  in  a  whole  system  of  tactual  and  kinaesthetic  impulses 
coming  from  the  left  arm.  We  would  expect  such  a  wealth  of 
sensory  impulses,  intimately  concerned  as  they  are  in  so  many 
everyday  habitual  coordinations,  to  serve  as  exceptionally  strong 
stimuli  to  readjustment  for  the  same  reason  that  we  expect  the 
human  infant  to  learn  more  easily  and  quickly  to  localize  parts  of 
his  own  body  than  external  objects.  Strange  to  say,  however,  of 
the  six  subjects  in  this  group  only  three  reacted  rapidly  to  this 
effective  complex  of  stimuli.  The  other  three  were  absolutely  un¬ 
influenced  by  the  stimuli  from  their  own  bodies.  One  was  at  the 
conclusion  of  the  series  in  absolute  ignorance  of  even  the  ap¬ 
proximate  position  of  his  unseen  localizing  hand !  Thus  there 
are  evidently  striking  individual  differences  in  the  extent  to 
which  the  development  of  a  new  spatial  habit  may  be  conditioned 
by  stimuli  from  bodily  position. 

7.  The  new  spatial  coordination  formed  under  the  conditions 
of  our  experiment  was  retained  for  long  periods  of  time,  func¬ 
tioning  at  a  considerable  per  cent  of  its  effectiveness  even  after 
a  lapse  of  from  one  to  two  years.  This  is  in  line  with  experiments 
on  the  retention  of  other  bodily  habits,  and  is  one  among  other 
indications  that  the  learning  process  involved  in  the  acquisition 
of  the  new  habit  is  of  a  sensory-motor  character. 

8.  The  new  coordination  is  not  merely  specific  for  the  par¬ 
ticular  conditions  of  its  formation,  but  maintains  itself  when  the 
experimental  conditions  are  changed.  It  even  in  some  cases  shows 
a  transitory  influence  on  reactions  to  ordinary  objects  after  the 
glasses  are  removed.  This  shows  that  with  our  type  of  experiment 
it  is  possible  to  study  quantitatively  the  process  of  discarding  an 
acquired  spatial  habit-system.  Stratton  found  that  after  the  re¬ 
moval  of  his  glasses  his  localization  of  ordinary  objects  was  in¬ 
terfered  with,  there  being  now  a  tendency  to  make  the  opposite 
type  of  error,  but  he  was  unable  of  course  to  gather  quantitative 
data  on  the  extent  of  the  interference. 

9.  The  new  space  habit  seems  clearly,  for  some  individuals, 


THE  DEVELOPMENT  OF  A  NEW  SPATIAL  CO-ORDINATION  95 


to  function  in  general  everyday  situations.  This  conclusion  is  of 
practical  significance  in  indicating  that  this  type  of  experiment 
may  be  useful  in  investigating  the  question  of  degree  of  general¬ 
ization  in  the  acquisition  of  spatial  habits. 

10.  There  are  striking  individual  differences  in  the  extent  to 
which  various  sensory  factors  contribute  to  the  formation  of  the 
new  spatial  coordination,  in  the  time  required  for  its  development, 
and  in  its  strength  and  stability  once  acquired.  For  most  sub¬ 
jects  tactual  and  kinaesthetic  factors  are  very  efficacious,  but  for 
some  they  have  apparently  no  influence  at  all.  Vision  is  effective 
for  all  our  subjects,  but  in  different  degrees.  Hearing  seems 
possibly  to  be  efficacious  for  some,  but  is  unquestionably  not  an 
influential  factor  for  others.  For  some  the  new  coordination  is 
easily  disturbed,  for  others  not. 

Such  considerations  as  these  point  emphatically  to  the  need  for 
extensive  quantitative  investigation  of  the  whole  subject  of  the 
acquisition  of  spatial  reactions.  It  seems  quite  likely  that  much  of 
the  disagreement  concerning  pathological  cases  as  well  as  normal 
reactions  in  the  genesis  of  spatial  experience  for  individuals  may 
be  due  to  a  failure  to  consider  the  possibility  of  wide  individual 
differences  in  the  matter. 

11.  There  is  no  evidence  from  these  experiments  that  the  new 
coordination  was  formed  on  any  other  than  a  purely  sensory- 
motor  basis.  At  first  it  was  thought  that  knowledge  of  the  nature 
of  the  error  might  be  a  factor  making  for  readjustment,  but  the 
control  experiments  without  knowledge  disproved  this  hypothesis. 
The  later  experiments  abundantly  bore  out  this  conclusion.  While 
such  factors  as  interest,  conscious  shifting  of  attention,  emo¬ 
tional  attitude  and  the  like  undoubtedly  influenced  the  type  and 
rate  of  progress  of  the  readjustment  or  learning  at  various  points, 
most  of  it  occurred  on  a  purely  mechanical  or  automatic  level, 
while  the  subject  was  entirely  unaware  of  the  nature  of  his  re¬ 
actions.  Even  in  the  visual  and  tactual  series  the  subject  was 
aware  only  of  the  end  results  of  his  reactions,  which  were  in  no 
case,  according  to  the  reports  of  the  subjects,  under  ideational 
guidance  or  control. 

12.  Perhaps  the  most  significant  result  of  this  investigation 


q6 


MARGARET  WOOSTER 


is  the  demonstration  that  it  is  possible  to  secure  accurate  and 
extensive  quantitative  data  on  the  problem  of  the  factors  in  the 
development  of  space  perception,  through  the  use  of  relatively 
simple  experimental  procedure.  We  are  keenly  aware  of  many 
defects  both  in  apparatus  and  in  procedure.  In  the  course  of 
the  experimenting,  however,  we  have  seen  ways  of  obviating 
these  defects  which  promise  much  in  the  way  of  future  investiga¬ 
tion  of  the  problem. 


